The answers to many questions asked on the forum can be found in the Official Railway Equipmemt Register or ORER for short. Published quarterly it contains info on every car in interchange service. It tells info on.railroads like number of engines, interchange locations, reportong marks car numbrrs, service and dimensions. Railroads tnrow them away when new ones come out. If you can befriend someone at your local railroad you can often get.one for free.
Older copies sometimes show up at train shows and on eBay. I’ve got a couple of issues from the 1970s and 1980s, which is roughly around the time period I am modelling.
These are extremely helpful for determining if a car was in service in your era.
Found on ebay:
Al Westerfield (maker of high quality HO car kits) also sold CD copies of ORER’s. He has retired and the business sold. I do not know if the new owners will be offering the CD’s.
edit 7/5/17 Westerfield open and has ORER’ on CD.
http://www.westerfieldmodels.com/ Enter store to find them.
The NMRA sells a reprint of the 1953 ORER
Dave Nelson
I got a real April 1954 ORER- close to the period I model- at a train store for $5 25 years ago. I have gotten more for that $5 than any purchase ever. I made a special heavy matte-board slipcase for it to slip it in and out of my bookcase with less handling damage.