Postal Guides

The Hong Kong Government issued Postal Guides (Post Office Guides) annually since the early days but I am unable to find many of them from the 1930s and 1940s.

I have gone through the holdings of the Hong Kong and UK Public Record Offices, Hong Kong Library and Chronicles & Directories but there are many unaccounted for.

Does anyone have knowledge of where else they may be found or any ideas on this matter?

Thanks in advance