We live in a Lustron home. They built in the late 40's. They are assembled like an erector set. The house is entirely metal(porcelain baked-on steel). We can put a magnet anywhere in our house. By anywhere I mean ceiling,roof,doors and all walls,inside or out. Our house has steel sliding doors throughtout the home instead of traditional wood ones. It is a very small house,only a little under 1100 sq.ft.. The house has 13 tons of steel and was built in less than 3 weeks. Each one of the homes has a unique serial number as well as a model number,kind of like a limited run of a product. The only statistics I have on my model is there are 912 tiles on the roof and it only took me an hour and a half to build the roof. It is built on the large grey baseplate.