Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

   A number of scale models of that engine have been made by several makers, and in different sizes. PM Research has one (listed under “Solar Engines”), it seems too small to be 1/4 scale, but could be a 1/4 scale of a smaller original, if the originals were made in different sizes (I believe they were?). The variation in sizes and makers probably explains the differences in prices.