China. (French Indo-China). 1951. Air Mail envelope addressed to Hanoi bearing French Indo-China SG 186, 20c carmine and SG 192, 50c brown tied by Hanoi. Viet-Nam date stamp, underpaid with 'T' hand-stamp and bearing French Indo-China postage due SG D213, $1 red/yellow tied by Saigon arrival, on reverse boxed slogan cachet. Scarce single dollar franking postage due on internal cover.