Mark,
That's a great summary of the situation, and probably represents pretty much how RGRPC is looking at it (although you covered some issues we haven't even talked about yet).
In the short term we are looking at ways to make the 19 as reliable as possible. Because we don't have the cash to do anything else, and we figure the 19 is a keeper, so the money won't be lost. But the 19 will be hard pressed to do some of things we need it to do. We will need to keep a few spare traction motors in inventory! And from what Marvin tells me they are a bitch to change.
Long term we need to look at a bigger and more modern additional diesel. With regard to the additional diesel, we believe there are some good candidates out there, but first we need enough money in our pockets to be able to negotiate seriously (asking prices tend to be high).
What kind of prime movers to use in the 19 is an interesting debate. Clearly turbo charged engines work better at altitude. But whether that is a good choice for the 19 seems to depend on which expert you talk to. My guess is, for any number of reasons including those you suggest, it makes more sense to put that kind of money into a new loco.
Thanks for the analysis.