Quoted from Pinkitten:
You might want to consider going keyless. I like keyless as it really simplifies access. Just an option. Pinball Life carries them as do other suppliers. The size seems to be standard from late 80s pins to the present.
I've been doing these on all my games. The downside, when I take them to shows I have to swap in real locks, but they save a lot of time at home.