Great story about Custer. Actually, The hamlet of Radebaugh was a flag stop on the PRR mainline going back to 1900 or so. A small station, more like a shed, stood near where the cutoff is for the SWRR. My uncle used the PRR passenger service daily for decades to commute to the Westinghouse plant in East Pittsburgh. Also, One of PRR's engineneers lived in Radebaugh. I knew his grand kids very well when I was a kid.
If I wanted to go to the Greensburg/foundry side of the old tunnel, I would drive to Thor road to the RR bridge area, park, and walk and look for the cutoff to the old tunnel. Or just find the tunnel from Carpet Palce, described above, walk over the old tunnel, around the old coal mine, to the Greensburg side and investigate from there.
Westmoreland Glass Company, in Grapeville, burned down some years ago. It was once famous for its decorative glass. I toured their museum about 45 years ago. All hand blown fancy stuff. They located in Grapeville because of the abundant natural gas available there as well as the siding with the PRR. At the time, all of the employees/residents of Grapeville had free natural gas for there homes.
Ray