Ozvegemite and stillcallozhome
Thanks for the help.
Exciter - I understand you to say CASA will not permit you to sit the ATPL exams if you have previously been issued a CASA ATPL certificate on the basis of other qualifications eg FAA ATPL. Thus one should sit all ATPL exams prior to attempting ATPL conversion. I would have thought as long as you paid a fee to sit the exams they wouldn't care who took them!
I have also read comments on these forums that some airlines in Oz require all flight training to have been undertaken in Oz. What degree of truth in that? If it is policy it is obviously a flexible one depending on availability of suitable Australian trained pilots.