I have never done any upholstery stuff, so I started sort of small. I decided to fix the door panels that were a terrible mess. The original panel on the left, and the one I made on the right. Close enough.
The fabric part (imitation leather) was in pretty good shape, despite the panels themselves having rotted badly.
Test fitting the fabric. I decided to glue it in place.
Gluing it together.
The finnished door.