Whatever it is used for now, it looks like it was originally a tuscan red Pennsylvnia RR streamlined sleeping car. A similar shade of red was used by the Norfolk and Western.
I tried to track the car down further--as being sold to the DOT in later years-- but did not have any luck. If anybody can read the writing in the middle of the car, possibly I can track it down.
The window pattern makes it look like it was originally built as a sleeper, i.e a coach would have a long row of identical windows.
Assuming it was bought in the massive 1950 Pennsylvania orders, tracing it to a specific train would be almost impossible for me as the Pennsy was a huge railroad, really huge. The records I have do not do a consistent job of showing which cars were built for which train, at least in a huge order placed by PRR.
But I would still like to see an written proof that such a car was bought by PRR or N&W and actually sold to DOT.