I remember a fad in the 70s where people engraved a number on all their stuff. I think it was called Operation ID.
I remember my dad doing that.
Same here but it was their SS# they were engraving.
I hated that trend, it’s destroyed the collector value of a huge number of guns. Nothing like turning over a minty Smith or Colt and seeing 123-45-6789 electro-penciled in the trigger guard.
Sometimes it ticks me off so much I feel like using the number to get a credit card and use that to buy the gun.