Laos. (Uruguay). 1954. Envelope addressed to 'Poste Restante' Vientiane, Laos bearing Uruguay Air Mail Yvert 144, 27c brown tied by Malounais date stamp '12th Feb 54', underpaid with T' hand-stamp with m/s '10' in blue crayon bearing Laos postage due SG D28, 10p indigo tied by Vientiane/Laos receiver '4/3' on face. Very few Laos postage due covers are known.