Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Brazil - Pioneer Flight - 1931 (June 18), Dornier Do X Flight pre-printed cover from Salvador to Porto Alegre, franked by five stamps, tied by Salvador ''18.VI.31'' ds, black flight marking, ''21.JUN.31'' arrival postmark of Porto Alegre on reverse, mounted on page from a Collection, VF, Est. $200-$250, Scott #C17, C18 x2, C19