Odd stamp on G41

Good day! There isn't a German semi-auto forum here, so thought I would post this under general rather than Mausers. Anyway, I have a matching 1943 Walther G41, but it has the oddest stamp on the side of the butt. In large font it is stamped 8-12-20. What on Earth would that be for? It is not a serial number, and doesn't make sense for a date of any sort. Inventory code for some sort of Allied evaluation depot? Some sort of horrible government registration stamp? Doesn't make sense a museum would stamp something like this on the stock, although I have seen museums do some serious dumbass stuff. Any thoughts appreciated. The stock is original to the gun, with the serial number worn but legible on the underside wrist, and the original WaA stamps are faintly visible on the left side.

Thanks

Ed

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I have seen firearms from the Canadian War Museum with the same sort of inventory numbers.

Stamped into the stock???? :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek: :eek:

Ed