There are no narrow gauge NdeM 2-6-6-2s surviving, but rumor has it there is one of the standard gauge examples lost down a canyon in the 1920s and never recovered. I do not have my information handy, but it came from Hector Lara, an enthusiast in Mexico who is fairly well known doen there. In one of the R&LHS annuals, there was a complete NdeM roster, which showed one of the older series of 2-6-6-2s written off in the 1920s, while all the others lasted into the 1950s and 1960s. If I ever find the info again, I can give you the name of the canyon..