One more unexpeted find! I stared to remove paint for the drivers side cab corner replacement and found way more bondo than I expected! The quarter panel is almost 3/4" out past the "door jamb" area. It might be easier to just remove it and fab up a fourth door
The truck cab's door jamb is still in place and a B post would not be the hardest thing to scratch build, but who knows! I need to dive into my magazine archives and find that 2wd 4 door crew that was built a few years ago. He listed what he did to get a fourth door.
Kevin