An old Western came on tv and a little surfing revealed this to be the featured engine.
http://locomotive.wikia.com/wiki/Nacionale_de_Mexico_No._650
Mr. B, this would make a great model in two versions- the modernized one shown here and an earlied-up version with diamond stack and cowcatcher to go with the early 4-4-0.
Full movie clip:
https://m.youtube.com/watch?v=sFWGuxRc3l0
The engine appears in the first 5 minutes or so, a little later on in a ridiculous scene when a posse offloads from flatcars already on horseback with the horses jumping off without a ramp, and supposedly later on at the end.
Warning: this is a REALLY TRITE Hollywood Western of the old school, probably one of the last. Every gimmick in the world. Plus "Liberty, Texas " is a real town, but it is not in the desert of West Texas but just east of Houston on the Gulf Coast prairie.
Executive summary: beautiful train, terrible movie.