@coach joe- Thanks for your comment Joe. I have not seen either S-2 that you have perhaps you could post a picture sometime. Especially of the Air Force S-2. I was assigned to Wright Patterson AFB, Dayton , Ohio from 1970 -1973 as an AF officer then worked there from 1973-1987 as a civilian engineer. In the early days, we had a train that moved some things around the base and I remember the blue locomotive. I was always going to take pictures of it but somehow never did and then it eventually just went away. Missed opportunity for sure.
Don