Towed some of the Sea Land containers on their trailers during my tour in Vietnam. Thought it would be fun to have one on a flatcar, just for grins.
I found a trailer on ebay(that guy that sells lots of parts/etc) Made a hollow wood container and covered it with aluminum printing plate I scored lines and rivets in, used duct tape foil for the corners/edges. Old Delton flat car I got cheap off Andre at Marty’s I O.D’d. Got the decals designed, will get them printed off soon.