Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Germany - Zeppelin Flights - 1931 (May 13), Baltic Sea Flight postcard on leg Friedrichshafen-Berlin (Round Flight), franked by Zeppelin stamp 1m carmine, tied with on board ''13.5.1931'' ds, ''Un Bord des L.S. ''Graf Zeppelin'' two- line confirmation marking in blue (no violet confirmation), VF and scarce, Sieger #108, Est. $150-$200, Scott #C35