Bill Ashton, formerly of Microplas and Weltex, joined with Ted George in the 1960s and made the "Tiki", of which three were made. Is this one of those? I can't find a corroborating picture.
...and we have a winner!
Built in Southland by Bill Ashton and Ted George (somewhere reported as
Asthon & George Ltd, active in boat building).
Here you are a pic of the 2nd of the 3 bodies done:
(Source: a very cool book about New Zealand cars I just received
)