In thinking back to the layouts of the 50’s, I have been on a casual search for a very long time for some houses that my dad had on our layout. IIRC, they were wood or heavy card stock with wood frames, but the windows and doors were clear (or translucent) plastic. I’m leaning more toward wood than card stock, as I think they were textured, as in having overlapping boards like shiplap. For all I know, they could have been from plans in Popular Mechanics, or Popular Science of which he had a huge collection. As a matter of fact, he built a 3’ long remote control model of a Coast Guard cutter from one of the magazines, which I think my brother still has.