diff --git a/Assets/Scripts/ServerShared/ItemData.cs b/Assets/Scripts/ServerShared/ItemData.cs
index e2bc01fb2..b416cfef0 100644
--- a/Assets/Scripts/ServerShared/ItemData.cs
+++ b/Assets/Scripts/ServerShared/ItemData.cs
@@ -276,9 +276,9 @@ public abstract class ItemData
     
     [Inspectable, CultInspectorTextArea, JsonProperty("description"), Key(2)]
     public string Description;
-    
-    [Inspectable, JsonProperty("creator"), Key(3)]
-    public CultRecordRef<Faction> Manufacturer;
+
+    // MessagePack key 3 belonged to a removed creator/faction reference field; do not reuse it. That provenance
+    // now lives on FactionProductData, and branding is derived, never stored on the design.
 
     [Inspectable, JsonProperty("mass"), Key(4)]
     public float Mass;
diff --git a/tests/Aetheria.Shared.Tests/AetheriaStoresTests.cs b/tests/Aetheria.Shared.Tests/AetheriaStoresTests.cs
index 12a961e69..1542950f0 100644
--- a/tests/Aetheria.Shared.Tests/AetheriaStoresTests.cs
+++ b/tests/Aetheria.Shared.Tests/AetheriaStoresTests.cs
@@ -29,7 +29,8 @@ public sealed class AetheriaStoresTests : IDisposable
         var faction = new Faction { Name = "Adrasteia", ShortName = "ADR", PrimaryColor = new float3(1, .5f, .25f) };
         faction.Allegiance[cache.Upsert(faction)] = 1;
         cache.Upsert(faction);
-        cache.Upsert(new WeaponItemData { Name = "Lance", Manufacturer = cache.RefOf(faction) });
+        var lance = cache.Upsert(new WeaponItemData { Name = "Lance" });
+        cache.Upsert(new FactionProductData { Name = "Lance", Design = new CultRecordRef<CraftedItemData>(lance.Key), Manufacturer = cache.RefOf(faction) });
         cache.Upsert(new InputLayout { Rows = new InputLayoutRow[] { new InputLayoutRowSpacer { Height = 1 } } });
         cache.FlushAsync().Wait();
     }
@@ -106,7 +107,7 @@ public sealed class AetheriaStoresTests : IDisposable
     {
         using var cache = AetheriaStores.Open(Catalog);
         var faction = cache.GetAll<Faction>().Single();
-        Assert.Same(faction, cache.Get(cache.GetAll<WeaponItemData>().Single().Manufacturer));
+        Assert.Same(faction, cache.Get(cache.GetAll<FactionProductData>().Single().Manufacturer));
         Assert.Same(faction, cache.Get(faction.Allegiance.Keys.Single()));
         Assert.Same(faction, cache.GetByName<Faction>("Adrasteia"));
     }
diff --git a/tests/mutation_tests.py b/tests/mutation_tests.py
index 70dcc370c..be918d028 100644
--- a/tests/mutation_tests.py
+++ b/tests/mutation_tests.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""Mutation tests for the Cut B provenance rules (docs/item-provenance-cut.md).
+"""Mutation tests for the Cut B and Cut C provenance rules (docs/item-provenance-cut.md).
 
 For each rule this applies its named mutation to an exact, unique anchor of
 source text, runs the one test that should catch it, restores the file
@@ -259,6 +259,22 @@ MUTATIONS: list[Mutation] = [
         test="RunSaveTests.CommitTakesRootsFromEveryZone",
         expect="red",
     ),
+    # --- Cut C: the manufacturer moves from the design to the product; the catalog fixture and its
+    # round-trip assertion (FactionIsASingletonInstance) must actually depend on that wiring. ---
+    Mutation(
+        rule="the catalog fixture's product carries the maker, not an unset reference",
+        file="tests/Aetheria.Shared.Tests/AetheriaStoresTests.cs",
+        anchor=(
+            'cache.Upsert(new FactionProductData { Name = "Lance", '
+            "Design = new CultRecordRef<CraftedItemData>(lance.Key), Manufacturer = cache.RefOf(faction) });"
+        ),
+        mutated=(
+            'cache.Upsert(new FactionProductData { Name = "Lance", '
+            "Design = new CultRecordRef<CraftedItemData>(lance.Key), Manufacturer = default });"
+        ),
+        test="AetheriaStoresTests.FactionIsASingletonInstance",
+        expect="red",
+    ),
 ]
 
 
diff --git a/tools/AetherDb/Program.cs b/tools/AetherDb/Program.cs
index 01334b388..662001dd7 100644
--- a/tools/AetherDb/Program.cs
+++ b/tools/AetherDb/Program.cs
@@ -40,7 +40,17 @@ public static class Program
     {
         var db = AetherDb.Open();
         var items = db.Cache.GetAll<EquippableItemData>().ToArray();
-        var products = db.Cache.GetAll<FactionProductData>().ToArray();
+        var products = db.Cache.GetAll<FactionProductData>()
+            .OrderBy(p => db.Cache.RefOf(p).Key.Value, StringComparer.Ordinal).ToArray();
+
+        // The manufacturer no longer lives on the design: it is derived the way Brand() derives it, from the
+        // first product in record-key order that sells the design. A design no product sells shows "(none)".
+        string MakerOf(EquippableItemData item)
+        {
+            var design = db.Cache.RefOf(item).Key;
+            var product = products.FirstOrDefault(p => p.Design.Key.Equals(design));
+            return product == null ? "(none)" : db.Cache.Get(product.Manufacturer)?.ShortName ?? "(none)";
+        }
 
         var kinds = new Dictionary<string, List<string>>();
         foreach (var item in items)
@@ -51,7 +61,7 @@ public static class Program
                 : item is WeaponItemData weapon ? $"Weapon/{weapon.HardpointType}"
                 : item.HardpointType.ToString();
             if (!kinds.TryGetValue(kind, out var makers)) kinds[kind] = makers = new List<string>();
-            makers.Add(db.Cache.Get(item.Manufacturer)?.ShortName ?? "(none)");
+            makers.Add(MakerOf(item));
         }
 
         Console.WriteLine($"{items.Length} designs, {products.Length} products\n");