I just finished a RGS video for release this fall. It's called "Riding the RGS". When the geese were put in service they essentially eliminated steam hauled passenger trains, the conventional type. The geese also had the freight sections for mail, express and other less than carload freight.
Jimmy Cooper is the motorman in a 1949 trip, and we see him twice in the film, once unloading mail and other stuff from the freight portion of Goose 5 at Placerville, and a cool sequence hooking up to the wire at Dallas Divide to use the telegraphone.
A couple of readers of this discussion board helped me with some locations.
Greg