@rplst8 posted:I don’t have an answer but MTH does have a 4 wheel passenger truck they use on the R50B express reefer. I don’t know if they’re prototypical on coaches though.
The MTH passenger truck on the R50B is the PRR 2D-P5 standard truck that was used for many decades as the standard passenger trucks under the R50s, B60 baggages, and the P70 coaches. They are specific to the PRR.
