I mirrored and swapped the cylinders, and used copper wire for the stack support. Great model, thanks.
Motor was "2pcs Intelligent Car Gear Motor TT Motor Robot Gear Motor for Arduino New" from ebay. I made simple extension bushes and cut away toe main frame. Also, I added lead ins the boiler. \Batteries temporarily mounted under tender. (Perhaps I will design a battery holder there if I build another one)
New longer Video here: