Your answer is along the lines I was thinking... but have no way of verifying. I'd also guess that Chama may have held on to some tools and capabilities longer, as it was also a division point, correct?
I'm guessing Sargent also started to decline as soon as the Mudhens came on the scene in the early years of the century, as most of those were used Salida to Gunnison. I could be completely wrong, but I'd think most of the stuff to be found at Sargent would have been hand tools, maybe a drill press or lathe if there was a steam boiler.
Very cool question...