Hello, Monty,
There should be a numeral cast into the top of the cam and this is the one you should order. You might also try other dealers by e-mail or 'phone through this link:
http://www.neilpryde.com/windsurfing-equipment.html. Select Australia, then select the NP targets nearest you.
If nobody can help you in Oz, try e-mailing NPMaui:
[email protected], attn Kevin Ozee. He has a great range of spare parts and international orders are not a problem for him.
Hope this helps.