Schuyler, 4 of the 8 cars have KC brakes which indicates they may be not correct for your era of the 1950's. For example the SP B-50-12's were rebuilt into all-steel cars by 1950. The latest photos I have of any are from 1949. Many PRR cars were rebuilt into all-steel X26C's while a couple hundred USRA X26's are listed in the ORER in 1955 (about 2% of the original fleet).
The Georgia cars had different roofs, as we have discussed here before. I love that black & silver paint but the models are a compromise.
