I guess I was thinking in terms of "rich guy wants a toy locomotive", similar to those who have 1/8-size Big Boys built. Surely it would not pay for itself hauling passengers in a commercial sense, but might eventually recompense the owner somewhat through the "engineer for an hour" deal. It's true, the money might be better spent at the C&TS saving real history, but the "rich guy with toy locomotive" types sometimes don't want to get involved with a group.
Given its simple construction, I don't think the wooden patternwork would be that difficult, provided one could obtain the use of larger machinery. A cylinder saddle,and possibly a few other parts, might even be scrounged from a derelict saddletanker.