I don't think the MRS1's were designed to go all the way down to 3' or meter narrow gauge. I believe they were primarily designed to go broad gauge for Russian and Asian railways. I also think they were too heavy for the DRGW narrow gauge. There was another Army locomotive by Baldwin or Whitcom (or maybe two engines) I believe, which was tested both on the DRGW and WPY narrow gauges. I have seen photos of them on both railroads in Durango and Skagway, possibly on the Narrow Gauge Discussion Forum website.

I never had a close look at the details of the MRS1's when they were used by the Alaska Railroad in the late 1970's (the ARR had 13 Alcos, and 5 of the EMD type), but I was under the impression that the bolster was adjustable to move the truck width out, but a new traction motor/wheel/axle combo were required to regauge them.