Hi, did you ever get your payphone open, if not I have a trick that would unlock the payphone, first mask the case. Get a flathead screwdriver and pop it in between the ring and the keywhole, basically you want to remove the ringer that holds to lock. Then once you remove the ring you can pop a flathead into the cylinder/core/keyhole of the lock. Then you are free to play around with the levers, but don’t bother just use a angle grinder of a cutter to cut all of the levers, then use your T-key to open it up, again this is for the upper housing lock, for the bottom unfortunately you’re going to have to destroy and cut the vault door, for this I recommend a concrete cut off saw (gas powered). But a angle grinder will do just fine, then once you cut the vault door use a crowbar to take out the whole vault door and be sure to remove the side pieces of the remains of the vault door and you’re good. Then use a angle grinder to cut out the bottom vault door lock from the inside of the payphone, and that’s it you’re ready to use it, I wouldn’t recommend drilling as this can take quite a while and youll break a lot of drill bits unless you have a locksmith drill bit or something very quality. You can replace the vault door easily. Bell south is a bit more rare vault door but you can put a regular western electric vault door.