British East Africa. (Kenya - Tanganyika). 1941. Stamp-less Official mail envelope headed 'On His Majesty's Service' addressed to 'No 7 Sub - Area, Dar Es Salaam cancelled 'E.A./ A.P.O. 2' date stamp '29th Oct 41' with framed "Q"/ 26 Sept' in violet on face and oval 'Air Letter Service Office/ Serial No/ Date 28-9-41/ Priority/Nairobi' in red on reverse. Scarce and unusual item.