Jan Wesselingh was an employee of Netherlands Harbour Works Co. from Amsterdam, working in Guangzhou (Canton) before WWII and in Hong Kong after WWII. I was brought in contact with two of his sons by Theodor A.R. Strauss, 1988-1993 secretary of Nederlandse Reünisten Vereniging China (NRCV, Dutch Reunists Association China), of which Jan Wesselingh was a member.
More narrative will follow.
Courtesy Wesselingh family archives