Rob and group,
The on line Ed Hawkins article you referenced covers only the ACF built postwar AAR boxcars with R-3-4 ends. Unfortunately, Ed hasn't published the complete roster.
I plan to make replacement resin castings that include 7 ft doors or 6 ft doors and the two adjacent side panels in order to model the more numerous model cars with narrower doors. Specifically the other PRR X43 classes with 7 ft doors and P&LE cars with 6 ft doors. I plan to cut down the Atlas doors to make 6 ft and 7 ft doors. With this approach the joint between the styrene body and the resin casting will be at a side panel joint and should be easy to hide.
Larry Kline
Pittsburgh, PA