[NZerFromHK]

They were actually pretty much voluntary migrants from the lower to mainstream middle class in Victorian Britain as NZ was never a penal colony. But from what I found at museums and government archives, it seems most migrants were either the Cornwall area, Oxfordshire, or northern England's industrial towns, and with some loewland Scots added into the mix.

[Myrddin]

That might explain the ultimate demise of Cornish as a living Brythonic language. It also explains the sense of British heritage instead of any focus on English or Scottish background.