John William Macintyre BROWN (aka Jack) [1900-1974]
He was born in 1900 and arrived in Hong Kong during the first world war.
Jack Brown was appointed Revenue Officer in the dept of Imports and Exports in 1921 in the British Colonial Civil Service. Not sure where he lived. Left HK in 1949.
The 1939 Blue Book lists a John William Macintyre Brown as Senior Revenue Officer, and notes he'd been promoted on 1st Jan. See:
Tony Banham's website has an entry for "Brown, John William Signalman 3866" on the "Hong Kong Volunteer Defence Corps" page that might be the same person: