bike lock question

i just got a new (used) bike, and was looking through my parents old bike stuff to see what i could find. i found an old kryptonite u-lock from 1983, still in its packaging. i know kryptonite recalled all their old round key locks because you can open them with a bic pen (awful) but they're not doing this program anymore.

my question is: is there anything i can do now? any other trade in programs? considering my bike is not worth more than $100 it seems silly to go buy a $50 lock, especially when i'm looking at what should be a perfectly good one right here. how fast will it get stolen if i use this old lock? any advice from brooklyn riders would help. i'm in crown heights, can probably keep the bike locked in my building most of the time but i plan to keep it locked outside if i bike to the subway to go to work.

thanks a lot!