Brazil 1931 DO-X Cover Collection. Four first flight DO-X covers, franked with various airmail issues, well written up on album pages, with 2 covers postmarked Aug 4 1931 at Rio di Janeiro, one to New York, the other to Trinidad, both with black triangular flight cachets; other 2 covers postmarked at Maranhao on Aug 7 1931, one to Havana, other to Belem, both with scarce purple cachets, covers fine to very fine. Estimate  $250 - 350. $0