Best Materials To Use Foam & Turnout Wiring?

GB,
Using foam, you generally want to avoid solvent-based products particularly lacquer and it seems most people like the thick,dense blue foram used for insulation. Sheet rock mud, etc., will all work but end up being rather heavy and crack easily. Rob K. pointed my in the direction of a product called Celluclay: a light weight cross between clay and paper mache. I've been pleased with the results and Rob may be willing to show you some of his handywerk with it.

For the component wiring for Marklin, check out: www.guidetozscale.com/index.html and www.z-world.com/instructions/ for Marklin component instructions.

Hopes this helps,

Mark