Hi Rob,
You might want to try a digital inclinometer to adjust your latitude. I am using one which I bought from
here .
This little device will tell you how accurate your mount latitude scale. If it's not accurate you can adjust it to be perfect using it.
Then with a compass you can point your mount to true South and I guess that's all you need. The only problem here is to find an accurate compass which won't cost you a lot. Cheaper compasses don't seem to me to be accurate at all. I have at least three including one digital built in watch and they never point to the same direction.
P.S. Using my digital inclinometer I found out that latitude scale on my EQ6 mount inaccurate and when it has 37 degree mark on scale it actually sets 35 degree angle.
cheers,
Mike