In BOLD, there seem to be more unnamed than named Australian species of Rhuma. Perhaps its one of those: EF05 looks possible https://bench.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=535431
The male underside here http://lepidoptera.butterflyhouse.com.au/geom/thiobapta.html does not fit above. It may be female or another moth ? I think I can just see antennae in 2nd shot - MAY be female (do not appear to be pectinate like males are).
Rhuma thiobapta appears to be the best match in Moths of Vic Part 4. That Vic record was for far NW corner (Neds Corner) On BOLD https://portal.boldsystems.org/bin/BOLD:AAF2497 confusingly there is also https://bold-au.hobern.net/specimens.php?taxid=72244
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