I had to go to a funeral home in Mahopac the other day that is across the street from the Lake Mahopac station. It is part of a business now but the sign is still up on the station. I would love to find where the Harlem station was. I understand it was very near the Put station.
Hope this pic is clear enough... according to “The Last of The Old Put...”, page 103, the sign is on the old train building (which is, at the time the book was written, an American Legion Post):