Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Latvia - Pioneer Flight - 1933 (May 28), Latvia - Africa Flight pre-printed cover from Riga to Berlin, franked by complete surcharge/overprinted set of five, tied by Riga Lidpasts special marking, Berlin ''31.5.33'' date stamp and ZWEIGLUFTPOSTAMT confirmation cachet, slight traces of mounts on reverse and minor foxing, still F/VF, Est. $1,000-$1,500, Scott #C9-13