1911 FIRST OFFICIAL U.K. AERIAL POST/LONDON ENVELOPE IN BRIGHT GREEN TO GERMANY. A very fine used London envelope in bright green from London to Magdeburg, Germany with KEDVII 1d and KGV Downey Heads ½d and 1d cancelled very fine strikes FIRST UNITED KINGDOM/AERIAL POST LONDON date stamps SP 9 11 with the scarcer die 5. Very attractive overseas usage. (Ref 102820).