It's just a lowly BSA lockring. It's not even the BB cup. It's hardly the end of the world if it gets a bit marred, or a couple notches get screwed up. It's not some irreplaceable piece of history or like it would get damaged beyond the point of usability. It's not even in a highly visible place.

Given the internal fillets and what appears to be a 1.37 marking on the cup, it's almost certainly BSA.