its not that easy in the eyes of the law, I would put money on that.
Prove you still own them, is as easy as “this here says you bought them”, show me where you have proof that you sold them. It works the same way you’re trying to play the cards, just the other way around. They have one up on you right off the bat, if they didn’t KNOW as some point you were in possession of them they wouldn’t be talking with you asking for them!
If you sold them, (or claim to have) show me the bill of sale and proof of supplemental income tax filing. They know you at one point had them (or they wouldn’t be knocking on the door) so without proof of sale, you are still fucked and one would think they have already have a legal backup plan to “I sold them” up their sleeve already!
While they are dumb, they aren’t that dumb. I would like to find out what the proper (see: how NYS expects you to prove you sold a weapon) way actually is, if that’s the card you want to gamble on if shit hits the fan.