There is a photo of an early car in RROBB V0l 3, pp129, whivh shows the truss rod on the end of the car. Some of the lower door guides on the end doors on some of the cars at Chama still show evidence of the original Queen (king?) posts, although the forked end has been cut off. Most of the RGS St Charles cars retained the complete lower end door guide to the end.
Dave G