I did some searching on the web and found a picture of an Officer in pistol training holding an early 5904 with fixed rear sight, ambidextrous safety/decocker with no spur on the hammer like used on a 6904.

Looks like British rule ended in about 1997.


OffBeat-News of the Hong Kong Police Force


Sounds like semi auto pistols are used by Tactical Officers while regular patrol and uniform Officers use blued S&W model 10 revolvers. The recent pictures from the protest show HK PD with model 10’s.