SEATO - South-East Asia Treaty Organization Block of Stamps

First Day of Issue SEATO SOUTH-EAST ASIA TREATY ORGANIZATION AUSTRALIA - FRANCE NEW ZEALAND - PAKISTAN Art Craft UNITED STATES UNITED KINGDOM THAILAND - PHILIPPINES MAY 31 9-AM 1960 D.C. SOUTH EAST ASIA TREATY ORGANIZATION SEATO ele 4¢ UNITY PEACE PROGRESS SEATO UNITY PEACE PROGRESS FIRST DAY OF ISSUE SEATO 4⁹ UNITY PEACE PROGRESS UNITY PEACE PROGRESS 4⁹ U.S.POSTAGE