Railroad Archives Online
- CollectionD0063 - Walter W. Ainsworth Collection
- Series005 - Pacific Coast Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- ItemWWAPC0264 - Pacific Coast Railroad caboose number 52 at Seattle, Washington, circa 1940.
- ItemWWAPC0273 - Pacific Coast Railroad wood caboose number 52 at Maple Valley, Washington in 1939.
- ItemWWAPC0275 - Pacific Coast Railroad wood caboose number 52 at Renton, Washington in 1943.
- ItemWWAPC0276 - Pacific Coast Railroad caboose number 52 at Seattle, Washington, circa 1950.
- ItemWWAPC0277 - Pacific Coast Railroad caboose number 52 at Seattle, Washington in 1951.
- 20 more...