These cars, being part of the Railway Express Agency's Equipment pool, could be found running anywhere in the US, and possibly even made it to Canada well into the 1960's and early 70's.
R50b Express Reefers
Prewar Scheme (1930's-Mid 40's era)

Postwar Scheme (Mid 1940's-1950's era)

1962 era "Keystone" Scheme

B60b "NonMessenger" Express Baggage Cars
Prewar Scheme (1930's-Mid 40's era)

Postwar Scheme (Mid 1940's-1950's era)

1953-1962 Scheme (Less REA Markings)

1962-1967 "Simplified" Scheme

Penn Central Schemes


For more details, please see BLLW's website