Neil,
The one and only time I was in Titirangi was in December of 1971, I do not remember seeing the plan then.
You might want to get hold of Bob Glading, who was my playing companion that day, who lives in Auckland. He won the NZ Open as an amateur in 1949 and then the NZ PGA a year or two later. He has an encylopedic knowlege of all things concerning golf in NZ.
Bob