I *highly* recommend fuji tungsten slide film for this task. Not just for its reciprocity, but, actually the sky becomes the most gorgeous, smooth deep blue when you do long exposures. A 3 hour example from my backyard, that I call "almost north" for obvious reasons, may be found on the second page of the gallery
here. There were no adjustments of colour for this; what you see is what I got. The blues are luscious, I tell you!
The tungsten film also renders artificially illuminated buildings quite accurately, a nice bonus. I have relied on this capability many times.
Interesting about the procedures for locating the pole Down Under. Funny, I lived for about 15 years below the equator and never once thought about the lack of a true south-polar star. When I came to the states and learned about polaris I was really amazed. But I was a kid without a camera I was more interested in whether the water spiraled the "wrong" way down the toilet