Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - United States - 1951, DC-4 Skymaster, inverted ''REVALUED 6c P.O. DEPT.'' on stationery envelope 5c red, very fresh, unused and VF. This error is listed but priced with ''-'' in the Cat., Est. $800-$1,000, Scott #UC19a