China. (South Viet-Nam). 1974. Illustrated (map of Viet-Nam) Air Mail envelope addressed to Saigon, underpaid with 'THO-PHAT (T)' hand-stamp and bearing Viet-Nam postage dues SG D15, 30c green tied by Saigon date stamp. Very nice item of commercial mail with Viet-Nam postage due on cover, not easy to find.