Re: Ouray motive power

Somewhere along the line the 317 and 318 swapped boilers, possibly at the scrapping of the 317 but it seems it was during an earlier shopping. I'd have to check my records on that one.
Regarding the tenders, and Dennis can check me if I'm wrong, that tender that is now behind the 346 is larger in capacity than most 2-8-0 tenders. Usually the C's carried 2500 gallons and that one is good for, I believe, 3000. This tender is distinctive because of the "broken" beading around the top sides. It was, at one time or another, behind 340, 341, 345 and 318 that I know of from photos. Wherever they needed a 2-8-0 with higher water capacity, this tender got swapped out. Interestingly the 345 took it to the South Park when the C-19s were leased to the C&S.
It is my understanding that there was some shuffling of lineside water tanks on the Ouray branch in the 30s/40s and the distances were longer than a standard C-class tender could handle if the engine was working hard. About this time the C's working the branch to Ouray showed up with our friend the big tender. The back up engine at Montrose had the other engine's standard tender parked behind it, usually not hooked up.
When the 340 went to Knott's in 1952 the little tender off 318 went with her. Up until the rebuilding in the early 1990s, when they stripped the paint right down to the metal, you could still make out the "318" under the paint on the back of the little tender the 340 carries now. If that weren't enough, the funky Baldwin F&CC trucks are a dead giveaway that something is amiss and not pure Rio Grande.
Of course, the Rio Grande played musical tenders a lot, when one would develop leaks or break a frame. We tend to think of a given tender as "belonging" to a certain engine but this is largely because this was the tender that ended up behind the locomotive in the final years. As Dennis noted, the Grande was also willing to swap a boiler here and there to make one good engine out of two. 317-318, 319-320, 42-283 are three that come to mind. Drives us fans and modelers nuts when builders plates end up on the 'wrong' boiler!