1937 MAIL LONDON TO ARGENTINE 2/6D SEAHORSE (SG450). Envelope (opened out for display) London to Rosario, Argentine with fine 2/6d Seahorse (SG450) and pair 9d photogravure (SG447) cancelled LONDON date stamps 16 JY 37. Sent via the French route and on reverse PARIS receiver 17.VII 1937 and BUENOS AIRES/ARGENTINA receiver 7.1937.21. Envelope fault on reverse. (Ref 104803).