diff --git a/scripts/cross_reference.py b/scripts/cross_reference.py
index 2967cfde..a0fc5241 100644
--- a/scripts/cross_reference.py
+++ b/scripts/cross_reference.py
@@ -427,6 +427,17 @@ def _resolve_archive_source(
     return result if result is not None else "missing"
 
 
+def _first_hash(entry: dict) -> str:
+    """The first hash an entry declares, strongest first, or ''."""
+    for field in ("sha1", "sha256", "md5", "crc32"):
+        value = entry.get(field)
+        if isinstance(value, list):
+            value = value[0] if value else ""
+        if value:
+            return f"{field}:{str(value).lower()}"
+    return ""
+
+
 def slot_key(f: dict) -> tuple:
     """The slot a profile entry fills: its entries on one slot are the
     versions its code accepts there, and holding any of them fills it."""
@@ -591,6 +602,8 @@ def _cross_reference_profile(
             "in_platform": False,
             "in_repo": in_repo,
             "source": source,
+            # What tells this file from a homonym another emulator wants.
+            "identity": _first_hash(f),
         }
         gaps.append(entry)
 
diff --git a/scripts/generate_site.py b/scripts/generate_site.py
index 824b848a..2ef9e64e 100644
--- a/scripts/generate_site.py
+++ b/scripts/generate_site.py
@@ -2979,25 +2979,44 @@ def generate_gap_analysis(
             for emu_name in matched:
                 emu_to_platforms.setdefault(emu_name, set()).add(pname)
 
-        all_src_missing: set[str] = set()
+        # One row per file to find: a name two emulators share is one file
+        # only when both declare the same hash. Keyed by name alone, Fallout
+        # 2's master.dat vanished behind Fallout 1's, and the three Sonic
+        # decompilations' Data.rsdk showed as one.
         src_missing_details: list[dict] = []
+        by_identity: dict[tuple[str, str], dict] = {}
+        entries = 0
         for emu_name, data in emulator_gaps:
             for g in data["gap_details"]:
-                if g["source"] == "missing" and g["name"] not in all_src_missing:
-                    all_src_missing.add(g["name"])
-                    src_missing_details.append({
+                if g["source"] != "missing":
+                    continue
+                entries += 1
+                key = (g["name"], g.get("identity") or f"emulator:{emu_name}")
+                row = by_identity.get(key)
+                if row is None:
+                    row = by_identity[key] = {
                         "name": g["name"],
-                        "emulator": data["emulator"],
-                        "emu_key": emu_name,
+                        "emulators": [data["emulator"]],
+                        "emu_keys": [emu_name],
                         "required": g["required"],
                         "source_ref": g["source_ref"],
-                    })
+                    }
+                    src_missing_details.append(row)
+                elif emu_name not in row["emu_keys"]:
+                    row["emulators"].append(data["emulator"])
+                    row["emu_keys"].append(emu_name)
+                    row["required"] = row["required"] or g["required"]
 
         if src_missing_details:
             req_src = [m for m in src_missing_details if m["required"]]
             lines.extend([
-                f"### Files to Source ({len(src_missing_details)} unique, "
-                f"{len(req_src)} required)",
+                f"### Files to Source ({len(src_missing_details)} files, "
+                f"{len(req_src)} required"
+                + (
+                    f"; {entries} entries, a file declared with the same hash "
+                    "at several places is listed once)"
+                    if entries != len(src_missing_details) else ")"
+                ),
                 "",
                 "| File | Emulator | Required | Affects platforms | Source ref |",
                 "|------|----------|----------|------------------|-----------|",
@@ -3006,7 +3025,9 @@ def generate_gap_analysis(
                 src_missing_details,
                 key=lambda x: (not x["required"], x["name"]),
             ):
-                plats = sorted(emu_to_platforms.get(m["emu_key"], set()))
+                plats = sorted(set().union(
+                    *(emu_to_platforms.get(key, set()) for key in m["emu_keys"])
+                ))
                 plat_badges = (
                     " ".join(
                         f'<span class="rb-badge rb-badge-info">{p}</span>'
@@ -3017,9 +3038,9 @@ def generate_gap_analysis(
                 )
                 req = "yes" if m["required"] else "no"
                 lines.append(
-                    f"| `{m['name']}` | {m['emulator']} | {req} | "
+                    f"| `{m['name']}` | {', '.join(m['emulators'])} | {req} | "
                     f"{plat_badges} | "
-                    f"{_source_ref_markdown(profiles[m['emu_key']], m['source_ref'])} |"
+                    f"{_source_ref_markdown(profiles[m['emu_keys'][0]], m['source_ref'])} |"
                 )
             lines.append("")
 
diff --git a/tests/test_audit_regressions.py b/tests/test_audit_regressions.py
index 1861a92a..14fedc5e 100644
--- a/tests/test_audit_regressions.py
+++ b/tests/test_audit_regressions.py
@@ -3569,5 +3569,20 @@ class TheGapReportKeepsItsShape(unittest.TestCase):
         self.assertIn("across the emulators batocera runs", text)
 
 
+
+class AFileToSourceIsAFileNotAName(unittest.TestCase):
+    """The gaps page keyed acquisition targets by name: Fallout 2's
+    master.dat disappeared behind Fallout 1's."""
+
+    def test_rows_are_keyed_by_name_and_hash(self):
+        source = (ROOT / "scripts" / "generate_site.py").read_text()
+        self.assertIn('key = (g["name"], g.get("identity") or f"emulator:{emu_name}")', source)
+        from scripts.cross_reference import _first_hash
+
+        self.assertEqual(_first_hash({"md5": ["AB", "cd"]}), "md5:ab")
+        self.assertEqual(_first_hash({"crc32": "1", "sha1": "F" * 40}), "sha1:" + "f" * 40)
+        self.assertEqual(_first_hash({}), "")
+
+
 if __name__ == "__main__":
     unittest.main()