Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Saar - Zeppelin Flight - 1931 (August 15-16), Muenster- Essen Flight cover franked by six adhesives, tied by ''13.8.31'' date stamps, Friedrichshafen ''15.8.31'' connection and red oval flight cachet, postmarked in Muenster on August 16, mostly VF, Sieger #121, Est. $150-$180, Scott #131-34