The 70's and 80's was a time when next to no one bought and rode an off the shelf race bike in Australia and custom frame builders were numerous. I remember one guy having a Bianchi but that may have been just the frame.
I had a custom Lennie Rogers frame built back then from Reynolds 531db but I believe that the previous lead you have would be better.
There really were a lot of custom frame builders in Australia at the time.