Using a photo of D&RGW C-18 #319 double heading with K-27 #461 as an inspiration, we briefly considered renumbering the 315 as the 319, but the switcher pilot, cab roof hose box and rectangular front number plate were too distinctive, so we went with 315 as a what if. Just because there isn't a photo doesn't mean it didn't happen.
315 leads 455 at MP 317.1 en route to Antonito.
319 leading 461 near Hesperus was a model for our RGS recreation. Photo courtesy of the Dorman collection.
Michael Allen