>C&Os were gone from Revenue Svc by 1940???
Actually, they were gone LONG before WWII.
The C&O cars were in the 20810-20999 number series. In 1913, there were 170 of these cars, in 1917, 149 cars, but by January 1925 the number series was gone, as were any hoppers with the identical dimensions. The cars MAY have been renumbered, but why would the car dimensions have changed in the ORER so drastically to make them untraceable?
Overall, Seley hoppers weren't very durable, which is why they barely lasted 25 years on the N&W, and as a car type really didn't survive the Depression, except for the late-built Southern cars. I think that's one huge reason why most in this hobby haven't paid a whole lot of attention to the cars, since they're mostly "off the radar" long before the time that most of the mainstream herd models.