Why so many errors on PRR steam locomotives - possible reasons.
Lack of data/inadequate research in earlier times
A significant number of PRR prototype O scale models were produced in the cast boiler "doorstop model". era , and still later in the early brass import era - all prior to ready access to PRR archive drawings and data. Absent railroad drawings, PRR models were sometimes produced based on drawings in Kalmbachs's Locomotive Cyclopedia that had dimensional errors. My pet pieve being undersized front air tanks on PRR I1's from MG, USH, Sunset, and MTH. To date no production PRR I1s has correct large diameter front air tanks - the most destinctive feature of the prototype. Steve Grabowski used to offer replacement I1s air tank kits at PRRT&HS meets
3 rail compromises:
The Samhongsa (Wiliams, Weaver) PRR E6, G5, H10, K4, and L1 all suffer from longer than scale engine length as a result of compromises made to provide clearance for high rail flanges running on O-31 curves.
Progress
Recent PRR O scale models by Key, Overland, Kohs, and Sunset 3rd Rail have higher prototype fidelity than earlier models as a result of importers collaborating with PRR fans that have obtained copies of railroad drawings from the PRRT&HS and other archives.
