China. (South Viet-Nam). 1974. Illustrated (map of Viet-Nam) Air Mail envelope addressed to Saigon, underpaid with 'THO-PHAT' tax hand-stamp and bearing Viet-Nam postage dues SG D316, 5p multi-colour (pair) and SG D317, 10p (pair) tied by Saigon date stamp with boxed slogan.
Very scarce Viet-Nam postage dues on commercial envelope.