There were two championships in 1971-72-73
You have listed the winners of the Over 3000cc series
Under 3000cc champions in the respective years were
1971: Gary Deakin (Heron)
1972: Danie Lupp (Rorstan)
1973: Dave Waldron (U2)

Wal: I think the likeliest date for the Taylor Timaru photo is 23/10/72. He was a non-starter there in both previous seasons