Hi chris ,
MY husband is a mechanic with similar experience to yourself and we are heading to Melbourne once our England home sells ! Soon i hope .... lol.
I emailed his cv to a lot of garages he was offered a sponsorship on a 457 visa job in Brisbane, Sydney and Melbourne, they seem to be on the look out for mechanics with good experience , he was offered 60000 in Sydney and 50000 in Brisbane and Melbourne ! Works out about 23 dollars an hour take home a 1000 dollars a week on the 50000 wage.
Good luck , keep trying and you will get there! That's what we keep telling ourselves :-)