CapnB

I see where there was something that was possibly stamped but rust from the frame is attached to the wood and I seem to be altering it by trying to remove the rust between the stock half and the frame - if it is really there. I also see vestiges of the number written faintly in pencil on the right grip. The pencil marking's legible digits are in the correct locations.
It would not surprise me for these to be replacements as this gun was very likely in an armory.