As there has been a discussion of the Interuban film on the FJ&G I will set you all to sleuthing.
A late friend of mine, Robert Gurley, during the late 1930s had the benefit of a motorcycle, still and movie cameras and he used them extensively on upState shortlines and electric systems. I have a couple of this works, one on the Utica trolleys is particularly well done.
Bob moved to Camp Hill, PA near his father-in-law, Richard Steinmets, another traction fan & author. Bob died about twenty years ago and I have been seeking his films ever since. He worked a summer on the Southern New York and those films would be of particular interest.
So, put on your deerstalker's caps, grab your magnifiers and do some sleuthing.