Italy got to the proof game a bit late. All those marks were beaten into that gun by hand, probably by some poor SOB who had a boss that was on him constantly.
Maybe it didnt get that mark, or, it was hurriedly stamped somewhere it really didnt belong.
Have you checked further, looking at both sides of the lug, under the extractor, or perhaps further up the under rib, keeping an eye out for a partially polished off mark? How about both sides of the forend iron? Internally on the action, paying attention to flat surfaces where the wood meets the metal?
Not trying to be too critical, but, those photos lack detail. If I try to expand them, they go soft immediately. Im not looking with a phone, either.
Good luck.
Best,
Ted
