In general, what’s the best way to find out what locos were on the roster of a particular road in a given year? (In particular, the PRR in 1961.) I can find sources that list when certain locos were built, bought, or entered service, but they don’t always say when those locos left service. What I don’t want is to have an engine on the layout that seems OK because it was built in 1955, but in reality was completely sold off by 1960.
A good place to start might be the Pennsylvania Railroad Technical and Historical Society. www.prrths.com They also have their own forum board (free to use) where you can post this question.
Stauffers Pennsy Power 2 book lists all diesels purchased by the PRR and their service life. You could probably justify any engine built prior to that date with the exception of the centipedes.