Canal Zone, 1914, 10c gray, "Specimen" overprint in red. With small hole control punch, corner sheet block of 12, o.g., never hinged (few large gum skips), purple date stamps and boxed "Return to Issue Room" handstamp affecting 3 stamps, small nick on bottom right stamp, otherwise Very Fine. Scott No. 37S  Estimate $500 - 750. $0 (Image)