From the 7-37 ORER
FM flat all steel 43191 to 43690 100000 lbs. capacity 497 cars
note PPP 120000 lbs. capacity 2 cars 43386 43595
There are 2 other notes listing changes in capacity - both from 80000 lbs to 100000 lbs. and from different # series.
From the 7-39 ORER
FM flat all steel 43191 to 43690 100000 lbs. capacity 495 cars
There are no notes for special capacity flat cars listed in 7-39 ORER for this # series.
I'm sorry but I don't have any ORER's between these. There may have been a second capacity change on the 2 PPP note cars from 7-37 and a 10-37 or there abouts ORER
might show if that is the case.