I agree, the crest is fake and I suspect the P proof is as well. Maybe that's the only stamps they had handy. I think the stock is in fact a replacement Keystone A4 stock as I have a scant that closely matches that one sans the phony stamps regarding the bolt notch. In my experience the notches varied quite a bit, none exactly the same but all following a recognizable pattern. They should have left it as was.
Kurt