I am also looking for that butter. Was it called Cow and Gate butter ?
I have a NZ contact and will ask her. Related to Godfrey Tuxeria, the Enmore manager's son who died in a bus bombing in the 1960's. The NZ contact brother in Scotland was also in the bus and wrote here some time ago. I am in touch with two sisters and brother, including their Enmore housekeeper in NJ, whom they met again after 50 years.