I believe someone on BikeForums had a link to this guy.
LockPickingLawer
It got me down a rabbit hole of watching him and his buddies picking some challenging locks. Maybe this and the picture of the key from the link by
Vintage_Cyclist Cyclist may be enough to get this picked.
Remember those combination locks that had 4 rings of 10 numbers. They were terrible. This doesn't look much better as far as security.
Oh, nice bike. Are you going to repaint, touch up the paint or leave it alone?
I don't blame you for wanting to keep it. I would too, even though it is not much protection. And the prices for these old locks is outrageous. Maybe someone is paying the price.