There are a number of flaws on many of the King George VI era stamps. Some are constant and some are temporary. The ones listed in the Stanley Gibbons catalogue have been verified as a constant flaw which means that it occurs on more than one identified stamp and at a specific place on the sheet (Row 3/ Column 1 for example).
That being said, not every constant flaw is listed by the catalog. Usually it depends on the flaw having an interesting characteristic and sometimes even a good name (like the Ascension Torpedo flaw).
The only listing I have seen for Hong Kong is a monograph "A study of the Hong Kong Definitive Adhesives of King George VI" by Nick Halewood and David Antscherl. This was published by the Hong Kong Study Circle in 1992. It does list a number of constant flaws.
If you are interested in King George VI flaws, I have a number of them listed on my web site. Currently there are over 200 flaws listed with enlarged images showing how to identify them. Use this link if you want to see it.
http://www.kgvistamps.com/kgvistamps/flaws.aspx