Yes, they are the same panel with modifications. The barn door configuration is a smooth panel and the clam shell configuration has holes cut out for the clam shell hinges. The piece also has underneath brackets welded in place to hold the hinges.
The upper piece is the same for all years 1947/55, this is the step inside the rear cargo area. The only year difference is the 1947/50 used a different spare tire carrier and the bolt goes through the rear step adjacent to the barn door lower latch.
