HSI historical data

I can download Hang Seng Index (HSI) historical data from Yahoo finance page, however, the data is only dated back to 31 Dec 1986. Where can I look for the full set of HSI historical data since 1967 when the 100 base point was set? I don't mind get all raw data for a price.

Why do you really want it? What will you be able to do with pre 1986 data that will assist your trading?