I just finished editing a video of Vintage Steam In The West with a WP 2-8-2. All silent films of course. There are also a couple of articulateds as well (403 and 404).
As for the Mexico 4-8-4's I remember hearing a recording on a record which had a title in Spanish as I recall. There was a cut there of a train at night at a place spelled something like this, Huehuetoca(?) Anyway there is lots of switching then the train leaves town in a hurry and its a superb recording with the whistle blarring. It had a higher pitch, and a squeel to it, as if it was out of tune. But that one made your hair stand up. That might have been mobile fidelity, but I am not sure. I saw some 4-8-4's from the train in 1963, but never saw them really in operation. We missed a lot of good stuff, but at least we got to go see and ride some stuff. We did the NG a couple of days. 268 was our engine from Pueblo to Mexico City. I was 12!!!
Greg