Track laying soon got going, using Peco code 100 and insulfrog points, on 3mm cork (bought a massive roll off ebay for less than £25, only used about half for the whole layout).

Three continuous circuits were planned, each spitting into three in the fiddle yard at the far end of the room from the door. Due to the shape of the room, I tucked a long platform against the wall down one side, thus maximising the useful width, and enabling fairly generous curves. Track gauges being used to aim for 42 inch on the outer circuit, 36 inches on the second one and 30 inches on the third one, though much of it exceeds these radii, and Mk111 carriages used to check clearances where necessary.

A diesel depot and small steam shed appeared.
Existing Hornby platforms were used, but they were going to be disguised ASAP.
Metcalfe card was used to disguise them, after rewhitening the edges, as can be seen in the last photo.