diff --git a/src/lib/services/catalog-repair-live.test.ts b/src/lib/services/catalog-repair-live.test.ts
index defa4949..58e39453 100644
--- a/src/lib/services/catalog-repair-live.test.ts
+++ b/src/lib/services/catalog-repair-live.test.ts
@@ -230,6 +230,36 @@ describeGuard("catalog studio live repair rehearsal (sandbox)", () => {
 		const offer = await reconcileImportedOfferIds();
 		console.log("REHEARSAL offer reconcile:", JSON.stringify(offer));
 
+		// Every furnidata entry whose classname maps to a unique items_base row
+		// must have id === offerid === db id (incl. cross-section copies).
+		const [uniqueRows] = (await db.execute(sql`
+			SELECT id, item_name FROM items_base
+		`)) as unknown as [Array<{ id: number; item_name: string }>, unknown];
+		const dbById = new Map<number, string>();
+		for (const r of uniqueRows) dbById.set(Number(r.id), r.item_name);
+		const byName = new Map<string, number>();
+		for (const r of uniqueRows)
+			byName.set(r.item_name, (byName.get(r.item_name) ?? 0) + 1);
+		const finalFd = JSON.parse(
+			await fs.readFile(
+				path.join(gamedataDir, "config", "FurnitureData.json"),
+				"utf8",
+			),
+		) as Record<string, { furnitype: Array<Record<string, unknown>> }>;
+		let badCrossSection = 0;
+		for (const section of ["roomitemtypes", "wallitemtypes"] as const) {
+			for (const e of finalFd[section]?.furnitype ?? []) {
+				const cn = String(e.classname ?? "");
+				if (byName.get(cn) !== 1) continue;
+				const offer = Number(e.offerid);
+				if (!Number.isFinite(offer) || offer <= 0) continue;
+				if (dbById.get(offer) !== cn) continue;
+				if (Number(e.id) !== offer) badCrossSection++;
+			}
+		}
+		console.log("REHEARSAL cross-section id mismatches:", badCrossSection);
+		expect(badCrossSection).toBe(0);
+
 		const afterState = await audit();
 		console.log("REHEARSAL after:", JSON.stringify(afterState));
 
diff --git a/src/lib/services/furni-data.ts b/src/lib/services/furni-data.ts
index d8e45ea3..e09f1805 100644
--- a/src/lib/services/furni-data.ts
+++ b/src/lib/services/furni-data.ts
@@ -536,6 +536,24 @@ export async function reconcileFurniDataWithItemsBase(): Promise<FurniDataReconc
 			}
 		}
 
+		// Normalize cross-section duplicates (e.g. a wall item listed in both
+		// roomitemtypes and wallitemtypes). The canonical copy already has the
+		// correct id/offerid; a stray copy may carry a legacy wrong `id` while
+		// its offerid still points at the right sprite. Only fix when the
+		// offerid maps to an items_base row whose classname matches this entry
+		// exactly, so we never guess.
+		const dbById = new Map<number, string>();
+		for (const row of rows) dbById.set(row.id, row.itemName);
+		for (const section of ["roomitemtypes", "wallitemtypes"] as const) {
+			for (const e of furniData[section]?.furnitype ?? []) {
+				const offer = entryOfferId(e);
+				if (offer <= 0 || Number(e.id) === offer) continue;
+				if (dbById.get(offer) !== e.classname) continue;
+				e.id = offer;
+				fixedIds++;
+			}
+		}
+
 		if (fixedIds > 0 || fixedOfferIds > 0) {
 			await writeFurniData(furniData as Record<string, unknown>);
 		}