The AC late frame guns are a very unusual variety. It is commonly believed that the guns were made after the war from spare parts in armorer kits. Walther put their factory code "AC" on all replacement parts. This variation should have no serial numbers of any kind on the gun. The barrel is from Sprewerke, the slide is Mauser and the frame Walter. Some of the small parts are hand made and the guide rods are modified grip screws!! However, the slide has the German firing proof of the e/s which would indicate it was test fired as a completed gun from the factory before the end of the war!!! A mystery and debate all in one pistol.................