On a 1911 map (Plate 3-4, Mapping Hong Kong), the even numbers start with 2, Queen's Road Central (QRC), the Grand Hotel, between Ice House & Duddell Streets.
Today that site is 8, QRC.
It looks as though the re-numbering happened some time in the 1960s. I guess it was triggered by the construction of the Hilton Hotel (2, QRC) and Beaconsfield House (4, QRC) in the early 1960s.
If anyone can confirm the date the re-numbering happened, please let us know.
Regards, David