Last Grand Prix meeting at Ardmore was 1962, by January 1963 Pukekohe had opened.
Both Auckland Car Club and Northern Sports Car Club used to run meetings at Ardmore called usually " Little Ardmore " meetings as they were Closed Club events. the last would have been in 1962.
Believe the only meeting after that was the 1989 Ardmore Classic / Historic meeting.
The " 30 years of Grand Prix Racing " event in 1983 was the Ardmore /Pukekohe event and as ERC says was held at Pukekohe.
There was a Magazine produced around the event .. I have the magazine so can check it out for you " Spyda " !!
The 1983 meeting at Pukekohe
Some information on a " Little Ardmore " from Milan Fistonic archives. an NSCC meeting