I'd agree with you duncan and might even say it's the "Whangaroa" as she did not have a radar tower behind the monkey island. The radar scanner was placed on the top of the crows nest on the main mast, although its a bit hard to define the detail with the bridge structure in the back-ground.
The photo would have to be pre September 1965 as this was the sale date to Union Steam.
Yes Steve these graceful ships had a short life with their original owners, strange that NZSCo built them with such small reefer space. But who knowns what the supposed shipping trends were back in the mid 50's.