So I have some friends who live in a log cabin by a lake. It was inherited after an uncle died. He left a safe in the basement and no one has been able to figure out the combo in at least 20 years. I'm sure a big part of that is they don't know how to dial in the combo properly even if they had the right numbers.
So here's the safe

Note the handle next to the dial. If I push down on the handle a little it locks the dial at certain "steps" like something is going into a notch. Otherwise the dial spins freely.
So before even trying to figure out the combo, I was wondering if someone could help me with
A) What's up with the handle? Is that normal?
B) What model of lock do you think it is so I can do some research on it.
C) Any other advice that might be helpful.
Here are some more pics.


Thanks for any help.
-Zenophryk