Hi Althea
Stretching the grey matter to some research I did about 25 years ago, the '1882 Freeholders Index' original returns were destroyed once the Index was (eventually) published. (They probably went up in smoke along with that year's census returns!).
It was a big undertaking for its time but it allowed the Government of the day to get some sort of fix on the ownership and value of land throughout the country. It had nothing to do with voting and everything to do with the potential to tax landowners - as the government still likes to do!!
Many of the 'freeholders' listed would have been unable to vote in any case - owners included women, businesses/companies, organisations, deceased estates, people who lived overseas - and, in some cases, had never lived in NZ, and minors (under 21 years of age).
It is a good 'snapshot' of the country at the time without ploughing thru' electoral rolls and directories. In slightly earlier electoral rolls, if you owned land in an electorate, you could vote there. So one person could be listed in 3 or 4 electorates because of their land ownership - if you're lucky, you'll prise the legal description of the land from the electoral rolls.
Best wishes
Elli