Portugal, Airmail, 1931 DO-X Flight card. 25c Postal Card with with two additional $10 stamps to San Francisco Cal., Lisbon cancels and also "Dornier DOX Flugpost 30 Jan. 31. 1929" datestamp, various cachets, well-struck "Correio Aereo Rio de Janeiro 22 VI 31" backstamp, minor edgewear, Very Fine. Estimate  $150 - 200. $0 (Image)