Opening rear door that is stuck W126?
 

I want to pull a door off at the PNP but the rear drivers door does not open, with either the outside or inside handles, I cannot pull the lock knob up it is missing and seized up (rod). No way to get inside the door while closed that I can see...any thoughts? I thought about cutting the B pillar but I think the latch will hold strong to the body and not easily cut out back there.

I dont think the B billar is the solution. It is just the hinging/pivot point.

You need to cut the C pillar and break/disconnect the door striker/latch mechanism. This will free up the rear part of the door so it can pivot on the B pillar hinges and check strap mount. Then you are free to remove the door.