For M. bigerella I have always looked for the white stripe along trailing edge of forewings connecting the basal, antemedial and medial lines as illustrated by the 2 ANIC moths (at top/not genetically tested) on BOLD. https://bold-au.hobern.net/specimens.php?taxid=127056 There are specimens from other sources with and without the stripe, with the same BIN number (does this mean they are genetically the same/close???) This ANIC one is close to mine https://bold-au.hobern.net/specimen.php?processid=ANICW1219-11 also a Gavin Cocks and possibly some WA ones. Perhaps it is M. bigerella
I think there is some suggestion of a dorsal connecting white stripe, so a worn M. bigerella seems most likely to me compared to the other named suggestions.