I know this is an old post, but I happened to come across it while searching for different information about PSP. I've done some research, and from what I can tell, the following are the former Troop S stations (in alphabetical order; I don't know the troop designations/numbers):
Belle Vernon, Fayette County
Chambersburg, Franklin County
Dunmore, Lackawanna County
Fern Ridge, Monroe County
Gibson, Susquehanna County
Harrisburg, Dauphin County
Hazleton [Valmont], Luzerne County
Highspire, Dauphin County
Milesburg (HQ), Centre County
Mount Pocono, Monroe County
Pittsburgh, Allegheny County
Quakertown, Bucks County
Swiftwater, Monroe County
Washington, Washington County
York, York County
I hope that helps.