1911 FIRST OFFICIAL U.K. AERIAL POST/LONDON POST CARD/W. S. LINCOLN (STAMP DEALER). A very fine post card in olive green with KGV ½d Downey cancelled fine strike FIRST UNITED KINGDOM/AERIAL POST LONDON date stamp SP 9 1911 die 4 to "Mr. W. S. Lincoln, The Oldest Established Stamp Dealer in the World, 2, Holles Street, Oxford Street, London, W." and also on front one of his superb advertising labels in dark blue. Very fine usage. (Ref 102891).