A lot of Fishing line will stretch, a no-no for pull-pull cable. Check out a fisihing line by berkley called 'Spider-wire'. It doesn't strectch. It's also smaller in diameter, allowing you to use a higher lb test rating for the same size. The brass tubing is ok, it's what i've used in the past, just make sure you run a loop around the tube, such that you have 3 pieces of line going through it prior to crimping. The other alternative is to use a braided plastic coated metal cable. I think Dubro has some available. Don't know if any of this is available in Australia. hmmm. maybe the spiderwire is! I just spied it online, available in New Zealand.

mcmike