Denver & Rio Grande Western also bought some C & O cars ( right off the assembly line ) from the massive order that Robert Young placed, which was later greatly reduced once plans for The Chessie trains were terminated. The RGZ baggage - dorm ( later converted to baggage - coach ), and the unique Yampa Valley Mail Dome - Lounge - Obs's which Rio Grande would make even more distinctive when they added those god - awful round - end door extensions so the cars could be used mid - train, were among the cars bought. I recall several diners as well.