That is a Mauser number.
I don't think the stock is original to the metal.
Notice the contour on the right side of the loading port? The wood is let out longer than the front ring.
My bet is that the stock is from a 318 W.R. which had the rear of the front ring shaved back. We have seen this done to some 318s but not on any others that I recall.
Any others think this could be?

CORRECTION!
I thought that looked like Rigby wood and recoil lug. I think just maybe it is a 350 Magnum stock!!
Look at all of that filler ahead of the front ring! Add that to the long cutout on the wood at the loading port and it makes me wonder...
Get a shot of the bottom. Bet there is some goofiness around the bottom metal too.
Never heared of using a standard action in a stock let out for a magnum, but I guess it wouldn't be impossibe.