Chris, the current Durango turntable was air powered when it came from Alamosa in 1923. But it was powered from the engine's air pump. In 1940, the D&RGW removed the standard gauge turntable at Funston yard (Glenwood Springs). The air motor from Funston was more powerful than the one that came from Alamosa in 1923. In 1940 the D&RGW setup the Durango turntable to be powered from an air compressor in the roundhouse. The original turntables at Chama and Durango (other places too) were hand powered. There are photos of K-27s on the hand powered turntable at Gunnison. New (second hand from the standard gauge) turntables were installed at Gunnison, Marshall Pass, Sargents, and Chama were installed in the 20s when the K28s, K36s and K37s were purchased.
I do not have my printed files handy so cannot give the exact days and cost of the air motor from Funston to Durango.