Thanks Bill,
I found a file online for 40 Foot cars that came complete as display piece. Using the measurements from the MTH 36' Woodsided Billboard reefers, I broke the model apart, scaled it down, added more features, a base to add MTH or Lionel Trucks and wheels and printed it out. Since the original file were not my design, I have these available to download on Tinkercad. I am in the process of renewing my subscription and I will upload them here too.
The rest of my designs I will not share, since I have the printed items for sale, and it takes about 2-3 days to design, scale and test print the items.
The Caboose is from a photograph out of a book.
I have designed and printed all the Open Air Amusement Park Coaches (Disney, Dollywood, Strasburg, etc., a 1836 John Bull Passenger car, and several buildings.