Very nice!!! love the detail!! and yes I modeled the train. I used MEL expressions to animate the wheels - the idea is to be able to move the train and the wheels move on their own including the pistons.
will save you headaches when you get to the animation - you don't have to key frame every single frame - all you key is the train. everything else is linked as a child or a group.
Solomon
Soreel GraFX
https://www.sowl.com