NM Choo Min Wang in Pacific Zone Championship, Sydney 1960!

I found an interesting photo and information from National Archives of Australia: regarding our first National champion NM Choo Min Wang (photo right) competing in the Pacific Zone championship in Sydney held in 1960. NM Choo Min Wang is Malaysia Champion in 1958 and 1971.

Baris Hutagalung - left (Indonesia) Choo Min Wang -right (Malaya) competing in the Pacific Zone championship in Sydney in 1960. New Zealand champion Ortvin Sarapu, standing and examine the position in the match between Indonesian champion Baris Hutagalung, left, and Malayan Choo Min Wang

The position after black 6th move is as diagram below

And Choo Min Wang choose to play 7.d4