Palomino Stampede Owners - Help requested.

I have a Coachmen Cadet, which is almost identical to yours. I had the same issue with the rear wall separation. Mine occurred when the rear shelf in front of the rear bed was removed. This piece is structural in nature to support the rear wall. I also removed the rear trim piece that has the white molding in it, and add some new screws down the strip, starting at the bottom and working up.

I should have looked at the rest of your pics before commenting! Great job being done!