Tucked away at 33A Vauxhall Road is the Devonport Museum. Their web site
A single large space filled with memorabilia from the area including interesting old maps of the area.
Note the opening hours - not every day and not all day. Very much worth a visit - give yourself 1-2 hours
Quite an interesting cookbook collection - this one proving that Kiwi's have been eating "foods of the world" for a lot longer than we get credit for!