China. (French Indo-China). 1937. Air Mail envelope addressed to the 'Franco-Chinese Bank, Hanoi, Indo-China' bearing France Yvert Yvert 338, 3f violet tied by 'Paris/R. de Vaugirard' date stamp, underpaid with 'T' hand-stamp and bearing Indo-China postage due SG D 145, 12c orange/ blue and SG D200, 1c red/orange tied by Saigon-Central arrival with framed 'Trouve a la Boite' and forwarded to Hanoi. Nice item of French Indo-China postage due mail.