Liberia, 1942, 50¢ on 4¢ Orange, First Flight Liberia - U.S. Barred Overprint. In Se-Tenant Pair with Bar Overprint Omitted, o.g., omitted overprint stamp lightly hinged, other never hinged, deep brilliant color, exceptionally fresh and bright, Very Fine and choice, a stunning example of the 50¢ on 4¢ Provisional Airmail Se-tenant Overprint Error; signed Stolow. Sanabria No. 51b. Scott No. C30, C20  Estimate $750 - 1,000. $0 (Image)