South Africa 1931, Aug 10 Windhoek  cds on South West Africa Airways Reg. airmail  Via Walvis Bay cover franked with 30d. mixed franking of 1931 Airmail 3d & 10d bilingual horizontal pairs SG 86-87 ; GV pictorial issue 3d. Pair .SG. 77 1 all  tied by Lugpos Windhoek airmail cachet (no date) addressed to London, no arrival cds.