I don’t see any scratches near the rear retention pin in these pics (not saying they’re not there). But... it looks like the “rear retention block” or whatever, is missing. There’s even a little gap between the stock and action where I suspect it went. Wonder if that part was metal on the B3s or plastic.
Does the gun still shoot? I’d take the sucker apart and give it a good line job and cleaning. If you want to keep it those stocks can look better with some TLC. Nice fun plinker or springer tonlearn with.