What distinguishes apiculatum from semipapposum is the leaves and stems. I am not sure from the sample of the leaves and stems that you have provided which it is.
The late season leaves coming from the bases of older leaves are indicative of semipapposum. https://apps.lucidcentral.org/plants_se_nsw/text/entities/chrysocephalum_semipapposum.htm I am at the beta testing stage with the app, so not long now.
Leaves appear woolly on both upper and lower surfaces, not green upper of C. semipapposum. Photo 2 does not show old dead stems usually seen on C. semipapposum. From the habit and size of flower clusters I would say C. apiculatum. Cosgrove 'Photograpic Guide to Native Plants of the ACT' has some good photos.