Carved planking seams into the home-made end walls of the gravel loader, then glued the end walls to the back wall with plenty of right-angle jigs and clamps. Front wall will wait until I have assembled the wagon-loading chutes and put them in place, and painted the building interior to protect it from the weather. With luck, the days will shortly be warm and dry enough to allow me to do spray painting outdoors. Indoors is taboo.
There are four pieces of 3mm ply that might be the sliding gates for the chutes: All are the same width, but one pair is shorter than the other; with no dimensions on the instruction sheets, I shall be guessing which to use .
Whatever I come up with, the gates won't slide; I shall seal them closed to keep the weather out. The kit was designed to be a working model: Load gravel in through a removable roof, unload into wagons via the chutes. Ingenious, but indoors only as far as I am concerned. Loading/unloading will be purely imaginary.
Speaking of weather resistance, I am thinking of using a piece of alumin(i)um flashing for the roof in place of the kit's four plywood sections.
Onward.