@Matt
The NZMS1 maps do not appear to include Stewart Island. I've not tracked down 1" maps for Stewart Island, though there are many dozens of other NZMS map series and one or another may include Stewart Island. Let me now if you find it! Most NZMS map series are available on Auckaland Uni's geodatahub.
(2022/01/02 04:15)
(2022/01/02 04:15)