Thanks TSG. Progress is slow but the building is finally looking like a building:

I expect the railing should be on the inside of the uprights, not hanging out over space, but that’s another compromise to allow for the large bases on tabletop model figures.

I suspect the convention of painting things red and white wasn’t around yet in the 1930’s, but I wanted a red and white aerial, and I think some artistic licence can be tolerated. I doubt they made them of wood either, but I had an old stirring stick and it seemed the right length. It was also so full of paint that after sanding there was no visible grain.

Nearly there now, just the glazing, steps, and a few details to go.
I other news, I found the figures supplied by @tin shed gamer for the mono-wheel featured upstream. Unfortunately getting them to fit the mono-wheel would require some serious rebuilding of the vehicle so it looks like I'll have to make another one.
Life can be so very hard...