Surface Letters To USA GPO PostOriginal vintage General Post Office GPO advertising poster Surface letters to USA 6d for the first ounce featuring a fun image of a British red letterbox marked with the ER crown logo on a ship sailing at sea and flying the Union Jack flag on it, passing a letter addressed to Mr Smith POB 1731 New York 24 U. S. A. with a London postmark to the Statue of Liberty against a blue sky background, the stylised title text below with letters USA in the stars