1937-40 range first flight covers (7) incl. 1937 South African AW experimental flight Lourenco Marques - Johannesburg on to Kenya with special statue Air stamp (type 5), 1938 DETA first flight Lourenco Marques - Luanda, Angola one of only 57 registered covers, another for Lourenco Marques - Lumbo, 1939 RANA Tete - Beira 5.7.39 (only 14 flown), 1940 BOAC Lourenco Marques - England - scarce, commercial cover. (Image)