Here are three pictures taken by Tom Moungovan, and posted with his permission. Tom was smarter than me, he made the effort to take a side trip to Rio Gallegos. When we were frequenting Argentina, there was so much steam that we had to make choices and I never quite made it that far south. As Olaf noted, the modifications made to these locomotives in the later years by Porta made them among the most modern and efficient steam engines. And they burned what they hauled. But even with those advances diesels took over in 1988.
Hopefully this will stir up some more discussion of this unusual line.
JBWX