I have tentatively identified this moth as Gnathothlibus eras.
If I am correct, then the find is exciting because according to Zborowski and Edwards - A Guide To Australian Moths, it is only found in Eastern Victoria.
The larvae of this moth apparently feed on Vitaceae and I am in a wine producing district.
I will, however, seek an expert opinion regarding correct identification and may add some more photos later. I was unable to get a clear shot of the moth's head because I had to scale a ladder to get this shot!