Hey ckvintage,
I know one on Russell Street in the CBD. He was recommended by a friend and I've personally used him to clean and regulate my POrikka which was running fast - not seconds but hours a day!!! Works great. Paid $20.
He's very happy to work on reps. In fact, he showed me a 45mm PO rep of one of his clients. PM me if you want his details. Warm regards.