Bit of google and I came up with this post
1 Download the referred to Opco directory and opcos.xml
Recrafted it for the 2degrees details ... mmc = 530 mnc =24
<OpcoEntry CCMNC="53024" Opco="2degrees" Country="New Zealand" Phone="22022022" PhonePrefix="+64" TrunkPrefix="0" DisplayLocalNumber="true" />
Created a subdirectory for this based on the example , and changed the appropriate details and filenames to reflect the 53024 ccmnc .
Plugged in the 2degrees sim and voila !
Previously I'd mucked around and couldn't get the device to register so had deleted and re added the device using the vf VMB app, but don't think this is required once you have the above sorted.
Data speed is excellent - faster than vf.