Hi Jim,
Here is my two bob's worth.
There are plenty of Mustangs in Australia but they are scattered all over the country and just not enough per capital city for any mechanics to specialize in the one brand. i am in Sydney and been an old school mechanic for the last 40 years and specialize in US muscle cars, know everything about old Mustangs but I still have to fix Corvettes, Camaros, Studebakers, Cadillacs, Thunderbirds, even Pontiacs (no offence)to survive. What you need to do is get involved with members of this forum and get to know people like Glenn70 and Shaunp and get a crash cource in basic mechanichs so you can understand how to fix your own car. You are an enthousiast after all, love your classic car, so learn how to fix simple problems yourself. If things get complicated..... post your problem and someone here will fix it for you.
Cheers.