I was there, after we lost the fight.
We were sent a letter telling us we had X (I think it was 1 year but can't remember, it was over 20 years ago) amount of time to remove, Make compliant or surrender for destruction our guns. I made my M1A's, SKSs & some other stuff compliant, I had to have a gunsmith sign a statement that my M1a & other stuff was compliant. But NO AK's, AR15's, H&Ks, ect.. , they had to go; I moved them to a relatives house out of the city.
I remember reading on here that NYPD fucked with one dealer who had a bunch of non compliant stuff in his shop.
Although some Schumk who ran a Gunstore/Range in Queens told me the NYPD was going around spot checking compliance, I Never heard of anyone actually getting checked & I don't think anyone ever surrendered anything for destruction.
I lived in the NYC Police state for 10 years under the ban, then moved out.