Just my 2-cents. I may be wrong but do not recall K-Line making a full set of PRR fluted SS passenger cars that match your(our) 16" #1000 business car. K-Line also made a 16" fluted SS Busch "Adophus" business car. They also made a PRR 19" smooth side tuscan #120 business car that matched their original set.
Below are five of my K-Line (the Georgia is MTH) business cars. My 6th K-Line car is the smooth tuscan blunt end observation car "Alexander Johnston Cassatt."
Ron