Hi Robert
Not sure what you mean by a "registered MR2 AW11 mechanic" but I've used and recommend a guy that worked on mine when I had it (SW20 turbo). He operates only on weekends in the inner northern Adelaide area and is Toyota certified and experienced as he's been working for them for over a decade.
PM me or email me if you want his details:
miljy008@live.com.auJosh