Storing parts/scrapping locomotives

I have always wondered where the narrow gauge railroads (standard gauge short lines too) stored parts and what kind of parts were stored?
I know the White Pass & Yukon Route, because of the distance and isolation, stored just about everything and had a warehouse for it.
But what about short lines? The Colorado narrow gauges?
And when a locomotive was scrapped, did the entire locomotive get scrapped or did the railroad keep any parts?
For example when the 485 was cut up, did the Rio Grande get rid of all of it? Or were the rods, air pumps, headlight, etc. scavenged for other locomotives?
Just curious.