Neat.
I remember reading in a magazine about a guy that does this, but to a greater level.... he not only builds scale model working motors.... but he does the transmission.... frame.... body.... etc.; the entire vintage car to scale model (and motorcycles too) from scratch! Not a R.C., but a true working scale model. For example, you could put gas in the scale motorcycle, start it up, and operate the clutch and transmission with your fingers and rev it through the gears while sitting on it's stand on a desk.
I wish I could find him on the internet right now to show you, but I read about this in a mag that showed his work with lots of full spread photos, and I forget his name.
He sells his work for tens of thousands per 'work'.
-Chris