Model 12 ID help

[TJH]

I just acquired a U.S. marked Model 12. Serial numbers match. The original barrel has been replaced with a 1946 dated 30" solid rib full choke barrel. The receiver has been electro pencil marked with US-MOD-3946. Butt stock marked on left side with what appears to be W.B. in a box with crossed canons below. My question is is it possible that the barrel was replaced by the military on 3 Sept 1946? Has anyone seen any Model 12's marked this way?

http://www.milsurps.com/images/imported/2016/05/IMG_1025-1.jpg

http://www.milsurps.com/images/imported/2016/05/IMG_1029-1.jpg

http://www.milsurps.com/images/imported/2016/05/IMG_1027-1.jpg

[Tom Doniphon]

I would think if the shotgun was reworked at an arsenal in 1946 you would find a rebuild mark on the stock. Arsenals were still marking long guns on the stocks during that time frame.

Is the 30" barrel Winchester marked?

[TJH]

Yes it is a Winchester barrel, marked with 46 on the bottom of the barrel.

[scosgt]

Nope.
Kleins Sporting Goods in Chicago sold tons of M12 trench guns in the 1950's with long barrels.
Although most of them were probably aftermarket barrels.
Someone changed the barrel to use it for trapshooting or bird hunting.
Very very common
No idea what the marking mean, but they are not military. And may have been done by a PD or Prison long before it was re-barreled.