French Indo-China. (Hong Kong). 1940. Air Mail envelope addressed to France endorsed 'Pan-American Airways/ via Trans-Atlantic' bearing French Indo- China SG 175, 5c purple, SG 191, 30c chestnut (4) and SG 209, 60c violet tied by Cao-Bang/ Tonkin date stamp routed via Hanoi and Hong Kong with 'Opened by Censor/Hong Kong' censor label tied by boxed '43' in blue/green and Dordogne arrival.