Have one of those Double Door In-A-Floor safe doors in my collection. It looks like this:
The standard lock used in those safes is a Sargent and Greenleaf 4160 Series safe deposit lock. Which model used depends on when it was made. The 4160 series was first made in 1945, and AFAIK it is still being produced.
If the door is older than 1945, it may have a different lock. It may also have been repaired or replaced and have a newer or different lock. But this is where I'd start.
Keep in mind that this safe door does have two relockers which are fired if the lock is punched. Will not give pictures or more information about the lock or relockers on the open forum.
Squelchtone is correct that your best bet is to get a decent safe tech to open the lock for you. If the tech needs to do destructive entry (ruin the lock itself), at least he/she will know what kind of replacement lock to bring along.
Gordon
Just when you finally think you have learned it all, that is when you learn that you don't know anything yet.
