The B&O's covered roundhouse in Martinsburg, WV (from which the equipment was taken) is still intact, and it's a really interesting structure.
Moving multiple locomotives over the mountains on wagons drawn by oxen has to be one of the most audacious things ever attempted during the Civil War, and Stonewall Jackson pulled it off. I do kind of wish they had taken some photographs when they were doing it, but of course documenting the event probably wasn't a major concern at the time.
-Philip Marshall