This 1918 1911 arsenal rebuild, (AA), has a barely legible and very small number 49 stamped just to the right of where the trigger guard bow meets the receiver. It was manufactured at Springfield. Although arsenal rebuilt it wasn't parkerized and has the original stocks. The barrel is marked, "colt .45 cal", and has clearly been replaced. The inside top of the slide is battered; as though material was trapped between the slide and barrel. Does anyone know what the significance of the "49" stamp might be? And why an arsenal rebuild would not have been parkerized and fit with bakelite stocks? Thanks for your interest and comments.