Found this site which has some historic maps for Hawaii.
The maps are circa 1891 to 1906 and there is an index to the maps at the end of each section. Makes sense since there wasn't much else to insure back then.
My interest in them was as a tool to authenticate nonconforming structures or uses. But these are limited to the Downtown area only. So far, i haven't been able to locate historic maps for other areas of the island.
Anyone have aerial maps from the 30's to 70's?