I have one of the first run Atlas Trainman C&O RSD-7's and I think it is a pretty good representation of the prototype. The color and lettering looks accurate. Only a few nits to pick - the model has a steam generator exhaust on the short hood which shouldn't be there for the C&O, the horn is a three chime and should be a 5 chime, the horn is mounted on the long hood behind the cab whereas it should be on the short hood in front of the cab, and there should be a bell mounted above the short hood headlight. With a few brass detail parts these are fairly easy to correct problems.
Running wise I'm not impressed. This engine has a TAS SAW board so it does not have speed control and low speed operation suffers. It also only has two pickup rollers and I've always had power pickup issues with Atlas 2 pickup roller engines (however, no problems with their 4 pickup roller engines).
When Atlas announced a new run of these equipped with ERR cruise commanders I preordered one, planning to turn my old one into a dummy with sound and add a power tether to the new engine so I could get 4 pickup roller power. But that was three years ago and the latest I saw on the new run was shipping in 2020. I'm not holding my breath about ever seeing the new ones.
Ken