Given that I now know that both the original works drawings and the modern scale drawings don't accurately reflect the wagons that were actually used on the Sand Hutton light Railway, I've had to take a few liberties with some aspects of construction. Specifically I've been unable to locate any photos showing the inside of the wagons in any detail. This means that the placement of some of the bolts, especially those in the floor have had to be estimated. It's also unclear if the end walls had metal strapping on the inside. Photos of the wagons at Deptford supply depot, clearly show strapping, but on other photos it is less clear. I've decided to add the strapping (inset into the planks as on the side doors) given that the clearest photos show it to be present even if it isn't on the works drawings. Anyway the following render shows the progress I've made today.
Each of those bolts has to be accurately positioned, and each has a matching nut on the other side of whatever it passes through, so you can see where a lot of the time goes when building these 3D models. With these in place though I think the upper body is now complete. There are some missing pieces but these will be added to the printed model as they will be two fragile if printed. Now I just have to finish the underframe before I can order a prototype print to see how everything fits together.