So, as a display, I was thinking of fitting a HO, N and z scale figure.
To do this I decided to build a section of a Platform, decided to do it in N Scale.
I had to scratch build it as I do not have a kit.
I measured the space I had as well as the height to the doors of a coach.
Then I did a quick drawing on CorelDraw to get the measurements correct.
I used 2mm CardBoard to build it and some Lego Blocks to keep everything square.

Piture 01.
Then for the deck, I used a very fine grid sanding paper (P180), I scribed some stones on the edge and put a layer of glue over the edge to smooth it slightly. Picture 02.
For the sides of the walls I printed some concrete pictures. Picture 03.
I wrapped the sides with the printed paper. Picture 04