Tonga, 1966 Stampless O.H.M.S. Cover to United States. 3 different round postmarks & handstamps including: black NUKUALOFA / 28 NO 66 / TONGA; purple TONGA / OFFICIAL PAID & purple TREASURY / TONGA, plus single line purple BY AIR MAIL handstamp, all nice strikes, fresh & VF. Original enclosure accompanies.