You are correct from what I can ascertain. This is also known as the "short Door" coupe and the doors are the same as the four door. (I have a '48 four door to compare it to.) Back to the seat issue again...The sedan and convertibles have a split back bench seat. I believe the seat I need for my coupe is a solid back because passengers do not sit in the back and do not need access. I was told that the solid back hinged at the top and swung forward from the bottom up for access into the storage area behind the seat. There was also a package tray that extended from the top back edge of the seat to the rear under the window. I would gladly put a split bench seat in it if it were correct. They are mush easier to find.
As for the stainless rear quarter moldings...it is longer than a convertible or a sedan due to the short door. That's why I have to locate them. I have some of the moldings for the sedan already and they are definitely too short.
Still no photos?