Ron Campbell is old-school and is highly recommended in the MOCA Vic club. But I think he lives in Ocean Grove (past Geelong). PM me if you want his mobile number.
I have also used Hallam Performance Exhausts and Tuning (8 David Lee Road, Hallam) (03) 9702 3030 - know their old school cars, and were recommended to me for work on my 65 Fastback by another member.
Others may know some closer to your location.