Finally found it on one of my favourite sites......
The car was originally built as the Normac Special with a Wayne equipped 235 cu in Chevrolet in-line six.
It then became known as the Chev Special when owned by Arthur Spargo.
The puzzle picture was taken at the Te Onepu Hillclimb at Hawkes Bay, New Zealand in 1961 when it was called the AC Special driven by the then owner, C.J.S. "Colvin" Algie. It was powered by a 216 cu in Chevrolet in-line six in virtually standard form.
The original photo in unaltered but lightly cropped form -