Plenty of people say that Omega service is patchy in OZ, with some even saying they have had watches returned in worse shape than they went in.
A quick google search should reveal a long time Omega independent who is in Melbourne unless he's given it away but I can't think of his name.
There are others in OZ like Nick Hacko and Max Schweitzer out of a small handfull who may be able to help you out depending on what you want.
Max did my last Omega movement service on a Co-axial and it worked out just fine as far as I can tell.
One thing to consider is case polishing where Nick has runs on the board but maybe Omega would do a better job馃憥
Your watch movement is basic ETA stuff so it won't be difficult to service at all.