Beautiful work, Jim! I know this thing really dragged you through the weeds, but it was well worth the effort. I had almost convinced myself that I really didn't need one of these, but I've just changed my mind. I'll build the body using Styrene sheets, like #13, so the siding matches the brass sides of my Overland coaches. You have provided a fantastic path to follow in both research and skill.
It will take a while before I get to it, but I'll do it. I will have questions!