In the summer, for his birthday, my boy got a Trampoline which came in a very large, very strong (double thickness) cardboard box. I thought it had possibilities for a small layout. It measured 42 inches x 16 x 8 inches deep. On the plan, the lid (with one side removed) is the scenic area. A portion of the base is attached to create a small fiddle yard.
Upottery is a small village to the north east of Honiton, in the Blackdown Hills. So I have imagined a light railway, similar to the Hemyock line on the other side of the Blackdowns, running from Honiton up the Otter valley. The nearby RAF base is assumed to have continued in use after war so has provided enough traffic to keep it going. I'm going to model it in late 50's/early 60s, but early blue diesels might also make an appearance.
Its going to be analogue DC, and uses Peco setrack, but DCC might be swapped in future.