Hi, sorry it’s taken so long for someone to reply, I figure you’ve probably solved this by now. Melody Wheels is the in vogue wheel builder in Perth at the moment. Other than that, most local bike shops should probably be able to source and install a suitable spoke for you. Maybe start with those you know sell Campagnolo parts. ELite Cycles would be a possibility? TBE can handle most stuff. Cycle Mania have been able to sort numerous wheel problems for me.