COLLECTIBLE: EGYPT, 1919, March-April, Emergency R.A.F. Air Mail Service. Faint but clear strike of Base Army Post Office Apr. 24, 1919 circular datestamp of Alexandria on O.H.M.S. cover to Controller of Munitions in Karachi, boxed "Aerial Post E.E.F." cachet of Alexandria, Base Army Post Office Apr. 25, 1919 transit backstamp of Port Said, violet "COO Base" boxed handstamp unfilled and Bombay censor marking, Karachi arrival backstamp, cover missing top right corner and minor horizontal file fold, still Fine and exceptionally rare, of the 120 covers thought to survive from this emergency service, surprisingly only seven covers are recorded used abroad with two of those to India. With 2018 B.P.A. Certificate