Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Germany - BALLOON POST GROUP OF 7 ITEMS: 1899-1918, three civilians picture postcards, representing various balloons, franked by 5pf green, and four free-frank military balloon post No.40 (cover) or 206 (3 cards), mostly F/VF, Est. $250-$300