The old driveway of Eucliffe seems to coincide with the modern day entrance into the development that replaced it (which goes by the rather bland- for HK at least - name of "56 Repulse Bay"). The old entrance can be seen in the next shot.
Once inside the driveway we can see the front entrance. I have no idea whether or not the place was still being lived in when this film was made, but it looks as though the small centre garden in the middle of the circular driveway was still being tended to (or quickly fixed up by the film crew?). The building still had a few years of life left before demolition, so it's feasible it was still being lived in at this time.
We even get a quick glimpse inside the hallway as the maid opens the door to let them in, and what looks to be a conservatory in the next scene - although , I must admit, I am only guessing that it was filmed inside the building. It would be great if anyone could confirm.