On many of our trips to the other side of the North Island, we pass a farm with this building set up on it in Turakina. Each time we pass it, I wonder about it and finally got around to searching for its history.
I only found two or three references/pictures. Apparently, it was a one-room school house that was dismantled and reassembled on the farm about 60 years ago.
Here is a link to a Flickr account with other photos: https://www.flickr.com/photos/brian_robinson_nz/11989609706