Hey Tommo,

I'm sure you can find someone based in Aus but for guaranteed quality I use these guys.

They are expensive but the parts are OEM and shipping takes about a week, shipping is typically cheap with small parts but of course the more you buy they will be happy to consolidate the orders.

Here is the link, I highly recommend them and have always used them when replacing and rebuilding all of my carburetors (have a browse through the rest of their gear there, probably one of my favourite on-line shops):

Dellorto & Weber Carbs On-line