Air Mail cover 1926 (4 March) O.H.M.S. envelope (380x152mm., folded and other faults) to "Wing Commander W.H. Pulford, O.B.E., A.F.C./C.O. R.A.F. Detached Flight/Khartoum" showing oval double-ring "ROYAL AIR FORCE/MIDDLE EAST" d.s. and marked "For D.H. 9A going to Khartoum on 4/3/26" and "to be handed to w/cdr. Pulford on his arrival" in red ink. Unique