@stephendinnen

One place to start is by reading in the FamilySearch Research Wiki Chinese Genealogy page here: https://www.familysearch.org/en/wiki/Chinese_Genealogy You can access the wiki by clicking "Search" and then clicking "Research Wiki" from the drop down menu on the home screen. Then search for Hong Kong or for Chinese Genealogy.

Another option, since you have a very specific inquiry, is to set up a virtual genealogy consultation here: https://www.familysearch.org/en/library/online-consultations when you schedule choose Chinese Ancestors.

Good luck with your research.