Thailand. (Hong Kong - Philippines). 1939. Air Mail envelope headed 'Cornelder's Scheepvaart Maatschappij N.V. Rotterdam' addressed to Manila (Philippines) bearing Netherlands Yvert 145, 20c blue, Yvert 150, 50c blue-green, Yvert 152, 1g blue, Yvert 212, 15c orange and Yvert 372, 10c violet tied by Rotterdam double ring '28th Aug 1939' with 'Per Luchtpost/ Par Avion' label and endorsed '35 gram', carried 'K.L.M.' to Bangkok with arrival transit ''2/9' and forwarded by Imperial Airways to Hong Kong with Victoria/ Hong Kong receiver 5th Sept', jusqu'a mark with 'bars' hand-stamp applied over 'Par Avion' blue label (Ian McQueen Type 60) indicating the end of Air Mail service and carried onwards by steamer to Manilla.
'Nils Ramm - Ericson' in Air Mails of Siam does not record any mail via Siam with the 'Jusqu'a obliterator via Hong Kong.
The 35 gram rate is an exceptional 7 times Air Letter franking.