I didn't see them before, but I wonder if it's the same group of cars purchased last year from a location near Meadville. I know they were in Olean at some point last year, but I don't know if they ever left. There were quite a few yellow (UP Armor yellow?) cars in that group.
At first glance, they looked like former Long Island P72's... But my eyes decieved me. Standard Budd cars... Where they came from, and what they're for, Is beyond me.