cover "P. Ft.W & C. R'y, Apr 23, 1875, Mahong'town Station", (Pittsburg, Ft. Wayne & Chicago Railway), clear blue octagon-shaped pmk. on 3c Green on white entire (U163) to West Chester, Pa., couple trivial cover toning spots, otherwise very fine, an unlisted Railroad and marking in Towle-Meyer and believed to be unique photo