בידספיריט | British WWI military mail in

British WWI military mail in Egypt: 8 NO 1917 stampless long OHMS stationary cv ex RFC unit via APO SZ 12 (GHQ L of C, ABOUKIR) to APB ALEXANDRIA, tied by strike of SC Proud-D2 pmk on LKD of use & FB-unrecorded ”...TRAINING WING | ROYAL FLYING CORPS” violet oval cachet ; b/s same day BAPO Z (ALEX.) using scarce SC Proud-D7 & rare BAPO Z LOD (Proud-D1) 5 days after Proud's LKD of use ; slit open at top, very fine.