I'm not sure how yours is assembled. On a 123 chassis, you remove the ash tray brackets and that allows you to slide the console cover and switches toward the rear to release a pin in the back of the cover. Lift up and press switches out from below. They should pry out from the top but on a 123, you would probably damage the wood finish. This would also give you better access to the wiring and another trouble shooting method. On a 123, I would switch the rear door plug on the bad side to the working side to see if it works. If it works, the console switch needs to be cleaned (or replaced). If it doesn't, it's wiring.

Did you supply power to the window motor and confirm that it is good?

Charles