Sarl,
UK CAA should be able to give you list of flight schools in Aus which have UK Examiner on staff. My understanding is that you can avoid this problem of requalifying back in UK by doing the training at these schools.??
Why go all the way to Sydney? Jandakot/Perth, (WA), is closer to home and has a huge expat population of Poms - so you'll never even notice the language barrier!
happy days