cover 1885 (13 May) envelope to England, marked "On active service no stamp procurable" at top and "From Major Mackenzie, Staff, N.S.W. Contingent, Sandbag Redoubt, Suakin" at lower left, showing superb "BRITISH ARMY POST OFFICE/EGYPT" with code "A" and apparently delivered without charge; the envelope with some age stains and roughly opened at top. Rare. Photo