Re: One left..

As to the possibility of a standard gauge NdeM 2-6-6-2 still existing in a canyon somewhere in Mexico, the name Tomellin Canyon on the way to Oaxaca comes to mind as this type was used there...just a stab on my part.
An aside on the NdeM 2-6-6-2's...although they had the appearance of a larger locomotive with the feedwater heater tube bundle up forward of the stack, they were actually smaller locomotives than the Uintah cousins in terms of power for this reason...1" difference in driver size.
For all the hype about the Uintah 50/51, their tonnage ratings were later adjusted by the railroad down to only 90 tons out of Atchee over Baxter Pass. This railroad humbled anything mechanical that was thrown at it. I walked part of the grade 2 summers ago & ended up shaking my head at how a rail line was ever contemplated there.