[emeritus]

I had a look in my book on the Hornby O gauge syatem, but it doesn't say what the material of the insulators was. It does say that their electric track was a straight copy of Lionel track of the 1920's, so that might be a lead to follow. As the operating voltage was generally no greater than 20V, heavy paper should be OK. You could impregnate it with wax for protection against damp for extra security. I believe that paper used to be used as insulation in telephone cables, and Ferranti used impregnated ordinary brown wrapping paper for the insulation of the coaxial distribution cables of his original 10,000 V AC mains installation.