1909, 4¢ orange brown, imperf, vertical coil, earliest known usage. Single tied by "Pittsburgh, Pa., Feb 23, 1911" machine postmark on green illustrated advertising cover to Vermont, with additional ad on reverse, Very Fine, an extremely rare and earliest document use of this imperforate coil, with only three recorded usages of this stamp all from the same correspondence; with 2003 A.P.S. certificate. Scott No. 346V  Estimate $750 - 1,000. $0 (Image)