For a safe that old the default would not have been 50 - 25 - 50
You don’t have to pay to have it opened, you can simply keep looking at a locked safe ………
Seriously though - if you don’t want damage, then the safe will require manipulating, and that is a highly skilled service that will cost you money, you maybe able to negotiate a better price if you were to take the safe too the locksmith and leave it with him to be done when he has ‘spare’ time but that’s probably the best you will do. It’s going to cost you $$