Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - United States - Canal Zone - Zeppelin Flight - 1930 (May 31-June 6), Return South America Flight mixed franking postcard to Germany, franked by five air post values, tied by Cristobal ''MAY 22. 1930'' ds, upon arrival to NYC uprated by Zeppelin 65c green and cancelled on May 29; German and American (type II) flight markings, Friedrichshafen ''6.6.30'' receiver, VF and rare, only 25 cards exist, PF certificate, Sieger #64 III, C.v. €1,600, Est. $1,500-$1,800, Scott #C1, C3, C4