I have just been through the hoops with CASA but thats another story.
You can now submit your Part 66 to casa for CTC and they will recognise it and issue a CAR 31 licence. this will have the AV restrictions but all you need to do is Air leg and will cost you around $260. Then when you have the Car 31 licence wait 6 months as they will replace them with CASA B1 soon.
Once casa issue the B1 as a real licence and not an MA im sure that removing the restrictions will become easier as they will have procedures in place themselves rather than rely on Av Australia
If you go Aviation australia it will cost you more bu you will get the full b1 sooner.
B1 in australia at present isnt a must have as the companies are not used to it yet