1893 electoral roll
Surname NAIRN
Given Name James
Number 1844
Electorate Otaki
Voting Qualification Freehold
Residential Address Carnarvon
Occupation Farmer
Property Detail Part secs. 103, 270, Mount Stewart
Surname NAIRN
Given Name John Liddell
Number 1845
Electorate Otaki
Voting Qualification Freehold
Residential Address Carnarvon
Occupation Farmer
Property Detail Part secs. 102, 270, Mount Stewart
and they are both there in 1881 electoral roll
So its before 1881 that they arrived
BYe
Althea
If you search James Nairn at Papers past there are quite a few possible entries
including obits stating "very old settler"
There are also NAIRN's in the Petone settlers dbase, my pc is running too slow to search