Weeds, I looked through your pictures before I commented. You definitely had the original clam shell tailgate , the barn doors were added later. Notice tb hinge openings for the barn doors were hand made and the tailgate hinge holes sealed. Also you can see the worn cables and hardware. If you look under the rear sill you will see remnants of the lower tailgate hinge mounts. Tim is correct, no barn doors prior to 1950.
I must say, you have always s been an inspiration to me with your build and I refer to your pictures often. Maybe this summer: might have my first drive in mine. It's only been ten years since I purchased this one....g