Garth Groff and Sally Sanford
Here are all five photos I have of C&O open MW cars. All were taken in the 1980s, and I think two were idler/tender cars for Burro cranes. All three cars were rebuilt from flat cars with added gondola superstructures.
912267 appears to be a 42' car (12 stake pockets) rebuilt as a gondola from series 80300-80399, 1929 cars built by and inherited from the Hocking Valley. Shaver says many of these cars were converted to MW service in the middle to late 1940s. This car could also have come from the similar PM series 16000-16099 which came to the C&O in 1947 as 216000-216099. The Red Caboose (now IM) model is a close match. This was photographed at Charlottesville from the old downtown depot platform before the station was sold off to become offices and the platform was enclosed.
912375 is also a 42' car. The eyes and cables on the shack's roof suggest anchor points for a Burro crane's hook. This car was photographed in Scottsville, Virginia, though I don't remember a Burro crane being around at that time. Possibly it was being held with other MW cars I saw there that were awaiting scrapping. That's my Toyota pick-up in the distance, well loved, but troublesome (it blew out several head gaskets when I could least afford to have it fixed).
940068 is a 52/53' car, apparently built from a welded flat. I have no information about welded flat cars on the C&O. This one is definitely a Burro crane tender. Note the extra step and handrails. This was photographed in the Charlottesville yard east of the old C&O depot.