I make a total of 150 who drove at (not necessarily in) NZ and Australian Tasman races 1964-69. Sources for NZ are varied (largely observation) and for Australia Neil Nicoll’s not always reliable A Record of Tasman Formula Racing 1960-69)
By the way, I found 143 people who drove F5000 in Australia and New Zealand over the period from 29.12.68 to 2.5.82. To count they had to drive at a race meeting where a F5000 race was held. How many do you think competed the Tasman Cup rounds from 1964 to 1975?
There were an additional 49 at NZ rounds 1970-75 (I had no easy source for the Australian races)
So 1964-75 total must be around 210-220