Folks, turned up a post on Facebook, supposedly a Jack Delano photo. March 1943 Argentine KS yard (attached).
Appears to be Southern 311025, in the 311000 to 311499 series, double door class XM (in my 1950 ORER anyways). If I judge by the lower sill and ends, it's some sort of rebuild, steel sheathing outside a formerly single sheathed frame.
Can anyone tell me more? It's got an odd rivet strip, horizontally, about 4' up. Also, I think those are reverse dreadnought ends, kinda funky.