Middle Division who had cars made by Atlas - did a PRR X29 Express version. The cars converted to Express for passener service had different grab iron configuration dictated by the FRA and heavier truck bearings to run at higher speeds. They were also equipped with steam and communication lines used by passenger equipment. I think Middle Division/Atlas did at least 6 different numbers. They did put different truck details and all the outside stuff needed. I don't know if PRR converted any other boxcars to express passenger service and I know of no other accurate models of any.
Another signature PRR car that built and used in passenger service was the R50B reefer which MTH of which did a very nice model. This is a 50 ft steel side car with a round roof with sloped ends. While built as a reefer it evolved into dry express service also. Since these were built for passenger service from the start, they have passenger trucks and essentail details.
