I think B.obovata is unlikely, It prefers bogs & seepages up to 1600m. B.graminea is a contender, honestly given what we are working with Brachyscome sp. may be better.
Brachyscome are definitely IDed on the shape of their seeds, but shots showing the side and underside of the head and leaves along the stem as well as the base would help. Your shot of the teh flower head showing number of petals and your base shot were a pretty good start but this is a tricky one