Jeff, I was told by one of your volunteers at the CRRM last September (I visited during the Thomas-themed weekend, on the Saturday, and spoke at length to the guy manning the turntable demonstrations outside the roundhouse) that there was a plan to make C-19 #346 capable of visiting other railroads, in the same way as is planned for RGS #20. Federal regulation issues were holding up the process however.
Is that the case? I was also told that K37 #491 was essentially trapped at the museum due to weight restrictions on the nearby highway bridges, and that as a result, she could not make any return visits to her old San Juan's stamping ground. But since most of the K37s already based down there seem to be out of service anyway, she isn't likely to be of much use.
#346 must have visited Durango during her Montezuma Lumber Company days, as she was based not far away, and I'm assuming visited the D&RGW shops there for repair work? If she could make a return visit down there, she could get a good run on a much longer line, and perhaps impersonate her scrapped sister #345 during photo charters. That would be appropriate as she is carrying #345's ornamental dome rings, after Bob Richardson managed to get them during a quiet swap at Durango in the 1950's. She could run with the vintage passenger stock on the C&TS as well.