First challenge was to form the tumblehome on the sides, I did this by rolling them heavily with a wooden dowel onto a piece of card, a little at a time until the profile matched the ends. Then I soldered each end to each side, using the brackets supplied soldered to the ends first. The kit comes with no instructions, so thanks to the NGRM forum on tips of how to assemble.
Eventually I got the whole body assembled, pretty square and without much solder on the outside. The corner joints have come out pretty well, so I'm pleased with the result!
Here it is on the chassis, posed next to a Vale of Rheidol brake van (by Parkside Dundas) to give an idea of size. I mounted the brackets for the floor 3mm up the ends, so the chassis is set about 2.5mm up inside the body, which looks about right - possibly slightly lower than the prototype but will look in keeping with my other stock.
Don't forget this kit isn't designed for any particular chassis, so I have had to cut a hole in the floor to accommodate the Kato chassis. That was hard work, I don't find brass as nice to work with as plasticard. The floor is intended to bolt up into the body using the holes in the brackets at the ends, as shown below, thus allowing the chassis to be attached to the floor and glazing to be fitted after painting.
However here I am not sure. The body will be much stronger if I solder the floor in place, using the side tabs to reinforce the body sides. It will be easier to add glazing and an interior from above, as will be painting it without a roof, so I will have to make the roof (not supplied) removable anyway. In any case, those bolt holes will clash with where I would want to mount couplings, and I will need to add underframe detail below the floor too. So that leaves me with the problem of how to mount the chassis - I can't get it to clip in, I might be able to drill holes through the coupling pockets for bolts, but that means new holes in the floor ...