Eric, here's a live link:
http://www.ukmodelshops.co.uk/catalogue/fct/puffer.shtmlI would think that those smoke units could melt the stack on a loco with a plastic boiler. Minitrix made some N scale steamers with diecast boilers that would be better candidates, but if smoke is a problem in HO, I don't even want to think about the pickup problems it would cause in N.