Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - China - 1931 (June 6), C.N.A.C. Pioneer Flight cover on line Tientsin - Beijing, then via Siberia to Europe, addressed to Great Britain, franked by seven stamps of the 2nd Peking printing, including three of $1 values, tied by special flight circular markings, bearing red Berlin Zentral Luftpostamt transit handstamp, vertical fold, still F/VF and rare, Est. $300-$400, Scott #252, 263 x3, 265 x3