Last safe I bought had an electronic lock. Bought a s&g dial for $110 and changed it out. Take the door panel off and the change out is easy, hole pattern was the same on mine. There was one hole that was only drilled from the factory that I had to run a tap into.
That's what I would look into once you get it open.
For the locksmiths here or ones that have changed out electronic key pads for dial locks, would the S & G 6730-100 be a compatible lock, like you are talking about? From what I have read, you have to watch out for the door thickness, to make sure the lock will work.