diff --git a/src/components/interests/external-eoi-upload-dialog.tsx b/src/components/interests/external-eoi-upload-dialog.tsx
index 435306e6..2ddd66fe 100644
--- a/src/components/interests/external-eoi-upload-dialog.tsx
+++ b/src/components/interests/external-eoi-upload-dialog.tsx
@@ -1,7 +1,7 @@
 'use client';
 
-import { useState } from 'react';
-import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { useMemo, useState } from 'react';
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { Loader2, Upload } from 'lucide-react';
 import { toast } from 'sonner';
 
@@ -9,7 +9,9 @@ import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Label } from '@/components/ui/label';
 import { Textarea } from '@/components/ui/textarea';
+import { apiFetch } from '@/lib/api/client';
 import { toastError } from '@/lib/api/toast-error';
+import { formatBerthRange } from '@/lib/templates/berth-range';
 import {
   Dialog,
   DialogContent,
@@ -34,12 +36,49 @@ export function ExternalEoiUploadDialog({ open, onOpenChange, interestId, onSucc
   const [signerNames, setSignerNames] = useState('');
   const [notes, setNotes] = useState('');
 
-  const mutation = useMutation({
+  // Fetched on open to power the default title:
+  // "External EOI — <Client> — <berth range> — YYYY-MM-DD". Without
+  // this the file lands as just "External EOI - <date>" which is
+  // unscannable in any list when a port has multiple deals closing on
+  // the same day.
+  const { data: interestData } = useQuery<{ data: { clientName: string | null } }>({
+    queryKey: ['interests', interestId],
+    queryFn: () =>
+      apiFetch<{ data: { clientName: string | null } }>(`/api/v1/interests/${interestId}`),
+    enabled: open,
+    staleTime: 60_000,
+  });
+  const { data: berthsData } = useQuery<{ data: Array<{ mooringNumber: string | null }> }>({
+    queryKey: ['interests', interestId, 'berths'],
+    queryFn: () =>
+      apiFetch<{ data: Array<{ mooringNumber: string | null }> }>(
+        `/api/v1/interests/${interestId}/berths`,
+      ),
+    enabled: open,
+    staleTime: 60_000,
+  });
+
+  const defaultTitle = useMemo(() => {
+    const date = signedAt || new Date().toISOString().slice(0, 10);
+    const moorings = (berthsData?.data ?? [])
+      .map((b) => b.mooringNumber)
+      .filter((m): m is string => !!m);
+    const berthLabel = moorings.length > 0 ? formatBerthRange(moorings) : null;
+    const clientName = interestData?.data?.clientName ?? null;
+    const parts = ['External EOI'];
+    if (clientName) parts.push(clientName);
+    if (berthLabel) parts.push(berthLabel);
+    parts.push(date);
+    return parts.join(' — ');
+  }, [interestData, berthsData, signedAt]);
+
+  const mutation = useMutation<{ data?: { stageChanged?: boolean } }, Error, void>({
     mutationFn: async () => {
       if (!file) throw new Error('No file selected');
       const form = new FormData();
       form.append('file', file);
-      if (title) form.append('title', title);
+      const effectiveTitle = title.trim() || defaultTitle;
+      if (effectiveTitle) form.append('title', effectiveTitle);
       if (signedAt) form.append('signedAt', signedAt);
       if (signerNames) form.append('signerNames', signerNames);
       if (notes) form.append('notes', notes);
@@ -54,10 +93,15 @@ export function ExternalEoiUploadDialog({ open, onOpenChange, interestId, onSucc
         };
         throw new Error(err.error ?? 'Upload failed');
       }
-      return res.json();
+      return (await res.json()) as { data?: { stageChanged?: boolean } };
     },
-    onSuccess: () => {
-      toast.success('External EOI uploaded — interest advanced to EOI Signed');
+    onSuccess: (response) => {
+      const stageChanged = response?.data?.stageChanged === true;
+      toast.success(
+        stageChanged
+          ? 'External EOI uploaded. Stage advanced to EOI Signed.'
+          : 'External EOI uploaded. Filed against this deal (stage unchanged).',
+      );
       qc.invalidateQueries({ queryKey: ['interests', interestId] });
       qc.invalidateQueries({ queryKey: ['interests'] });
       qc.invalidateQueries({ queryKey: ['documents'] });
@@ -100,9 +144,12 @@ export function ExternalEoiUploadDialog({ open, onOpenChange, interestId, onSucc
             <Input
               value={title}
               onChange={(e) => setTitle(e.target.value)}
-              placeholder="Defaults to 'External EOI - <date>'"
+              placeholder={defaultTitle}
               className="mt-1"
             />
+            <p className="text-xs text-muted-foreground mt-1">
+              Leave blank to use the default shown above.
+            </p>
           </div>
           <div>
             <Label>Date signed</Label>
diff --git a/src/components/interests/interest-eoi-tab.tsx b/src/components/interests/interest-eoi-tab.tsx
index 7f4c58d0..79d5853e 100644
--- a/src/components/interests/interest-eoi-tab.tsx
+++ b/src/components/interests/interest-eoi-tab.tsx
@@ -26,6 +26,7 @@ import { EoiCancelDialog } from '@/components/documents/eoi-cancel-dialog';
 import { EoiGenerateDialog } from '@/components/documents/eoi-generate-dialog';
 import { ExternalEoiUploadDialog } from '@/components/interests/external-eoi-upload-dialog';
 import { SigningProgress } from '@/components/documents/signing-progress';
+import { FilePreviewDialog } from '@/components/files/file-preview-dialog';
 import { apiFetch } from '@/lib/api/client';
 import { toastError } from '@/lib/api/toast-error';
 import { useConfirmation } from '@/hooks/use-confirmation';
@@ -103,6 +104,11 @@ export function InterestEoiTab({ interestId, clientId }: InterestEoiTabProps) {
   const portSlug = useUIStore((s) => s.currentPortSlug);
   const [generateOpen, setGenerateOpen] = useState(false);
   const [uploadSignedOpen, setUploadSignedOpen] = useState(false);
+  // Lifted preview state so the View button on every signed-PDF row opens
+  // the in-app preview dialog rather than navigating to a presigned URL
+  // (which the storage backend serves with Content-Disposition=attachment,
+  // forcing a download even when the rep just wants to inspect the PDF).
+  const [previewFile, setPreviewFile] = useState<{ id: string; name?: string } | null>(null);
 
   const { data: docsRes, isLoading: docsLoading } = useQuery<{ data: DocumentRow[] }>({
     queryKey: ['documents', { interestId, documentType: 'eoi' }],
@@ -125,6 +131,7 @@ export function InterestEoiTab({ interestId, clientId }: InterestEoiTabProps) {
           doc={activeDoc}
           portSlug={portSlug ?? null}
           onUploadSigned={() => setUploadSignedOpen(true)}
+          onView={(id, name) => setPreviewFile({ id, name })}
         />
       ) : (
         <EmptyEoiState
@@ -154,7 +161,13 @@ export function InterestEoiTab({ interestId, clientId }: InterestEoiTabProps) {
                 <span className="text-xs text-muted-foreground">
                   {new Date(d.createdAt).toLocaleDateString()}
                 </span>
-                {d.signedFileId ? <SignedPdfActions fileId={d.signedFileId} /> : null}
+                {d.signedFileId ? (
+                  <SignedPdfActions
+                    fileId={d.signedFileId}
+                    title={d.title}
+                    onView={(id, name) => setPreviewFile({ id, name })}
+                  />
+                ) : null}
                 {portSlug && (
                   <Link
                     // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -183,6 +196,15 @@ export function InterestEoiTab({ interestId, clientId }: InterestEoiTabProps) {
         onOpenChange={setUploadSignedOpen}
         interestId={interestId}
       />
+
+      <FilePreviewDialog
+        open={!!previewFile}
+        onOpenChange={(o) => {
+          if (!o) setPreviewFile(null);
+        }}
+        fileId={previewFile?.id}
+        fileName={previewFile?.name}
+      />
     </div>
   );
 }
@@ -193,10 +215,12 @@ function ActiveEoiCard({
   doc,
   portSlug,
   onUploadSigned,
+  onView,
 }: {
   doc: DocumentRow;
   portSlug: string | null;
   onUploadSigned: () => void;
+  onView: (fileId: string, fileName?: string) => void;
 }) {
   const queryClient = useQueryClient();
   const { confirm, dialog: confirmDialog } = useConfirmation();
@@ -399,7 +423,7 @@ function ActiveEoiCard({
             <h3 className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">
               Signed document
             </h3>
-            <SignedPdfActions fileId={doc.signedFileId} />
+            <SignedPdfActions fileId={doc.signedFileId} title={doc.title} onView={onView} />
           </div>
           <SignedPdfPreview fileId={doc.signedFileId} />
         </div>
@@ -581,22 +605,26 @@ function StatusBadge({ status }: { status: DocumentRow['status'] }) {
 }
 
 /**
- * View + Download buttons for a signed PDF. `/api/v1/files/[id]/download`
- * returns a presigned URL in JSON (rather than streaming the file), so
- * we fetch the URL via `apiFetch` and then either open it in a new tab
- * (View) or trigger a programmatic download (Download).
+ * View + Download buttons for a signed PDF. View opens the in-app
+ * preview dialog (lifted to the parent so a single dialog instance
+ * serves every row); Download fetches the presigned URL and triggers a
+ * filename-preserving download via the shared helper.
  */
-function SignedPdfActions({ fileId }: { fileId: string }) {
-  const open = async (mode: 'view' | 'download') => {
+function SignedPdfActions({
+  fileId,
+  title,
+  onView,
+}: {
+  fileId: string;
+  title?: string;
+  onView: (fileId: string, fileName?: string) => void;
+}) {
+  const handleDownload = async () => {
     try {
       const res = await apiFetch<{ data: { url: string; filename: string } }>(
         `/api/v1/files/${fileId}/download`,
       );
-      if (mode === 'view') {
-        window.open(res.data.url, '_blank', 'noopener,noreferrer');
-      } else {
-        triggerUrlDownload(res.data.url, res.data.filename);
-      }
+      triggerUrlDownload(res.data.url, res.data.filename);
     } catch (err) {
       toastError(err, 'Failed to fetch signed PDF');
     }
@@ -605,14 +633,14 @@ function SignedPdfActions({ fileId }: { fileId: string }) {
     <>
       <button
         type="button"
-        onClick={() => open('view')}
+        onClick={() => onView(fileId, title)}
         className="text-xs text-primary hover:underline inline-flex items-center gap-1"
       >
         <Eye className="size-3" aria-hidden /> View
       </button>
       <button
         type="button"
-        onClick={() => open('download')}
+        onClick={handleDownload}
         className="text-xs text-primary hover:underline inline-flex items-center gap-1"
       >
         <Download className="size-3" aria-hidden /> Download
diff --git a/src/lib/services/external-eoi.service.ts b/src/lib/services/external-eoi.service.ts
index c027042a..57934d4d 100644
--- a/src/lib/services/external-eoi.service.ts
+++ b/src/lib/services/external-eoi.service.ts
@@ -135,34 +135,43 @@ export async function uploadExternallySignedEoi(input: ExternalEoiInput) {
       },
     });
 
-    // Advance the interest stage to eoi_signed (no-op if already past it).
-    // We bypass canTransitionStage explicitly because the operator just
-    // brought concrete proof that the EOI is signed — that's higher
-    // confidence than a normal forward-jump.
-    if (
+    // Two concerns to keep separate:
+    //   1. Document metadata — always write `dateEoiSigned` + `eoiStatus`
+    //      from the upload. Even if the rep already advanced the stage
+    //      manually, the paper signing event needs a recorded date so
+    //      downstream surfaces (SkipAheadBanner, milestone strip, EOI
+    //      merge fields) reflect reality. Honour an existing
+    //      dateEoiSigned (don't overwrite if already set — covers the
+    //      case where the rep is uploading evidence for an event whose
+    //      date was already backfilled).
+    //   2. Stage advance — only when the deal hasn't reached eoi_signed
+    //      yet. Bypasses canTransitionStage because the operator just
+    //      brought concrete proof.
+    const shouldAdvanceStage =
       interest.pipelineStage === 'open' ||
       interest.pipelineStage === 'details_sent' ||
       interest.pipelineStage === 'in_communication' ||
-      interest.pipelineStage === 'eoi_sent'
-    ) {
-      await tx
-        .update(interests)
-        .set({
-          pipelineStage: 'eoi_signed',
-          eoiStatus: 'signed',
-          dateEoiSigned: input.signedAt ?? new Date(),
-          updatedAt: new Date(),
-        })
-        .where(eq(interests.id, interestId));
-    } else {
-      // Past eoi_signed — just record the document, don't touch stage.
-      await tx.update(interests).set({ updatedAt: new Date() }).where(eq(interests.id, interestId));
-    }
+      interest.pipelineStage === 'eoi_sent';
 
-    return { documentId: doc.id, fileId: fileRecord.id };
+    await tx
+      .update(interests)
+      .set({
+        dateEoiSigned: interest.dateEoiSigned ?? input.signedAt ?? new Date(),
+        eoiStatus: 'signed',
+        ...(shouldAdvanceStage ? { pipelineStage: 'eoi_signed' as const } : {}),
+        updatedAt: new Date(),
+      })
+      .where(eq(interests.id, interestId));
+
+    return {
+      documentId: doc.id,
+      fileId: fileRecord.id,
+      stageChanged: shouldAdvanceStage,
+      newStage: shouldAdvanceStage ? ('eoi_signed' as const) : interest.pipelineStage,
+    };
   });
 
-  const { documentId: docId, fileId: fId } = result;
+  const { documentId: docId, fileId: fId, stageChanged, newStage } = result;
 
   void createAuditLog({
     portId,
@@ -184,5 +193,19 @@ export async function uploadExternallySignedEoi(input: ExternalEoiInput) {
 
   emitToRoom(`port:${portId}`, 'document:completed', { documentId: docId });
 
-  return { documentId: docId, fileId: fId };
+  // Berth rules engine: a manually-uploaded external EOI is still an
+  // EOI-signed event for the rules that watch this trigger (e.g.
+  // auto-mark the primary berth Under Offer). Fire via dynamic import
+  // to dodge the circular dep between berth-rules-engine and the
+  // interest services.
+  try {
+    const { evaluateRule } = await import('@/lib/services/berth-rules-engine');
+    await evaluateRule('eoi_signed', interestId, portId, meta);
+  } catch {
+    // Swallow — rules engine failures should never block the upload
+    // that the rep has already completed end-to-end. The orphan-reaper
+    // path doesn't apply; a missed rule evaluation is a soft failure.
+  }
+
+  return { documentId: docId, fileId: fId, stageChanged, newStage };
 }
diff --git a/src/lib/services/files.ts b/src/lib/services/files.ts
index 917bc495..d51d07a7 100644
--- a/src/lib/services/files.ts
+++ b/src/lib/services/files.ts
@@ -149,7 +149,11 @@ export async function uploadFile(
 
 export async function getDownloadUrl(id: string, portId: string) {
   const file = await getFileById(id, portId);
-  const url = await presignDownloadUrl(file.storagePath);
+  // Pass the canonical filename through to the presign so MinIO/S3
+  // returns Content-Disposition with the original name. Without the
+  // override the file lands with the bare storage-key UUID (no
+  // extension) in every browser.
+  const url = await presignDownloadUrl(file.storagePath, 900, file.filename);
   return { url, filename: file.filename };
 }
 
diff --git a/src/lib/storage/s3.ts b/src/lib/storage/s3.ts
index bd64a0f8..8fea5087 100644
--- a/src/lib/storage/s3.ts
+++ b/src/lib/storage/s3.ts
@@ -293,7 +293,27 @@ export class S3Backend implements StorageBackend {
 
   async presignDownload(key: string, opts: PresignOpts): Promise<{ url: string; expiresAt: Date }> {
     const expiry = opts.expirySeconds ?? 900;
-    const url = await this.client.presignedGetObject(this.bucket, key, expiry);
+    // Pass response-header overrides to minio-js's reqParams so the
+    // browser sees the original filename / content-type instead of the
+    // storage-key UUID. Without this every signed download lands with
+    // a bare UUID and no extension. Filenames are escaped per RFC 5987
+    // so a name like "Étude.pdf" survives the round-trip.
+    const reqParams: Record<string, string> = {};
+    if (opts.filename) {
+      const ascii = opts.filename.replace(/[^\x20-\x7e]/g, '_');
+      const encoded = encodeURIComponent(opts.filename);
+      reqParams['response-content-disposition'] =
+        `attachment; filename="${ascii}"; filename*=UTF-8''${encoded}`;
+    }
+    if (opts.contentType) {
+      reqParams['response-content-type'] = opts.contentType;
+    }
+    const url = await this.client.presignedGetObject(
+      this.bucket,
+      key,
+      expiry,
+      Object.keys(reqParams).length > 0 ? reqParams : undefined,
+    );
     return { url, expiresAt: new Date(Date.now() + expiry * 1000) };
   }