Before Cosseys Farm - 1967 to around 1980 was Birdwood Road and Wharepapa Road,in early -mid 1960's - going further back was Ostrich Farm Road.
Here from Alan Boyle archives - taken on 35m colour film is a Sprite run by Auckland Car Club member Robbie Bark ..

Name: AH Sprite #41 Robbie Bark Sprite NSCC Ostrich Farm 1961 ish Alan Boyle photo .jpg Views: 749 Size: 86.7 KB

Number plates are the 1961 - 64/65 issue - the last of the non- permanent plates that were introduced in 1964 for cars.

Maybe time to put the NSCC Hill Climb venues into a time line - some details have been put on this thread - more to find and post.

As an aside Alan Boyle got joint FTD at the first running of Cosseys Farm Road in March 1967.. in Tomato the first of his Minis with a longstroke 997cc motor - ..

From Bob Homewood this the results ; March 1967 from "Club Torque " the NSCC Magazine

Name: NSCC #101 A results Cosseys Farm Hillclimb Mar 1967 Club Torque P1, Bob Homewood v2, 12346351_1.jpg Views: 696 Size: 160.1 KB

a photo

Name: Mini Race # 89 Alan Boyle Tomato 850 with 997 engine A Boyle .jpg Views: 701 Size: 126.8 KB

- " Tomato " from Alan Boyle archives.. the joint FTD car.

a photo of Alan, Bob and others at the event .. from Club Torque .. thanks to Bob homewood.

Name: NSCC #103 Cosseys Farm Hill Climb Mar 1967 cars 1,.jpg Views: 722 Size: 90.0 KB