Canal Zone, 1904, 5c blue, "CANAL ZONE" inverted, horizonal pair. Tied by purple "Ancona, Jul 9, 1904" cds on a 1904 cover to Colon, partial Christobal cds at left and receiving backstamp; cover slightly reduced at left, Very Fine, one of only two recorded examples on cover; with 1969 A.P.S. certificate. Scott No. 2a  Estimate $1,500 - 2,000. $0 (Image)