Just picked up my 86 420SEL today and drove it in to work. My wife complained that her seat back felt twisted. When I looked at it there is a very pronounced drop to the left if you look at the top edge of the seat. Is there any adjustment that can be done to square up the seat back?
Other than that the car is great. :D

You possibly has a broken spring(s). A new seat spring frame is about $110 or you may have an upholstery shop to replace just the broken parts. Once you have the seat off, you may as well replace the seat pad and repair the seat cover if needed. Some shops can repair the seat cover and match the materials very well.

David