Have you found the brand and model number yet? Once you do it is possible to get information on how the door is nailed down and just where the central cam is that operates the locking pins.

The door looks to be a goner but it is really just a sheet of steel. It might be possible to cut away this outside sheet, disassemble the works from the outside in, and then replace the door with another piece of sheet metal. It might never be a safe again but it would look cool and make a nice place to store wine bottles.

You could even cut out the front and replace it with glass so you could see your current wine inventory.