Heavy sarcasm warning.
Oh I understand now you have the lock not the key ?
Here comes the sarcasm
There are so many different keys for these locks !!!! ( ????)
My daughter got locked out of her pop up. It has the same style lock.
The first person we found with that type of lock, had the same key.
You might not be as lucky, but you could try, or go to a locksmith, before you start drilling.
I would address the issue sooner than later, so the fridge coils can be inspected. That vintage fridge, if it is original, is about ready to keep and eye on for dangerous ammonia gas leakage.
You can inspect it yourself….Look for a greenish/goldish colored goo, on the coil.