I am not really a model train buff. I know that any number of people are, and get great joy from model trains, but they have never really interested me that much. However---I have always been intrigued by Stephenson's Rocket, which was the first or second commercial train engine driven by steam. I was lucky enough to find a 3D model of this train, but it is made in a different software than mine. I can import it, and view it, even take dimensions from it, but I can not change the scale nor manipulate any of the part files. This model has steam cylinders 1.3" in diameter and the large front wheels are 9 3/8" diameter. I may rework the design to a much simpler configuration with 5/8" cylinders and 4 1/2" diameter wheels. I would start out by modeling and building the two engines.