Always good to hear from the expert.
Based on what you posted, and given the fact that in the 1950's there was a helper engine (or engines) stationed at Chama and big trains to move, I would guess that in the early 50's with the older flats in use the chances of a three engine train with a mid-train helper might have been a reasonably common occurance. What do you think. Wonder what the train registers would show.
But whatever the prototypical basis, I'd sure like to see something like Saturday's train happen again. Kudo's to Jay and the whole C&TS bunch for making such a train happen in 2006. And dramatic pix like have been posted make wonderful publicity for the railroad.
JBW