Canal Zone, Postage Due, 1915, 1c olive brown, "Specimen" overprint in red. With small hole control punch, top margin block of 12 with part imprint, o.g., never hinged, some perf separations in sheet margin, Very Fine. Scott No. J4S  Estimate $500 - 750. $0 (Image)

Canal Zone, Postage Due, 1915, 1c olive brown, "Specimen" overprint in red. With small hole control punch, top margin irregular block of 15, o.g., never hinged, purple date stamp and red boxed "Return to Record & Specimen Dept" handstamp at top, margin perf separations, Very Fine. Scott No. J4S  Estimate $600 - 800. $0 (Image)