They don't sell these anymore and there are better products now, but this was what was available in Sweden back in the mid 80-s. They had plaster-moulds before, but they were for bigger scale and, well, for only one brick/stone. You could as well buy some lego and paint them grey! :-D Thought I had what I needed for what I'm planning, but I'll have to cast (right at last?) new floors and walls and paint them. Found the instructions in the cellar, but I'm just going to do two walls and part of a floor that I can use as a background for different scenes. Scanned the instructions (sorry, in Swedish, but you can look at the pictures).