Hi Hally,
Firstly welcome to "The ODK Forums".
As I'm not in your neck of the woods I can't help you in any recommendations of where and who. But in saying that the best I can offer is that you go to your local Bowling Club and ask them who they use. Generally they won't use amateurs and as such I wouldn't either. Those guys won't steer you astray.
I have to ask the question, why a Diplomat and not a 33 or 45 ?, was it based solely on purchase price ?
Cheers,
BB.