Here are a few interesting and/or related links:
http://www.australiandressregister.org An online register of dress with an Australian provenance pre-1975.
http://migrationheritage.nsw.gov.au/exhibition/objectsthroughtime/convictbutton Part of a history resource. This page shows a convict button and explains its history.
https://www.coles.com.au/about-coles/centenary A history of the company.
http://localhistory.kingston.vic.gov.au/htm/article/579.htm A history of the Semco company.
http://www.thimbleselect.com A site to buy and learn about thimbles from Australia and elsewhere. Also some other sewing collectibles.
http://www.vicbuttonclub.com.au Website of the Victorian Button Collectors Club. Meets monthly in Burwood East.
http://trove.nla.gov.au Website of the National Library of Australia.
http://www.naa.gov.au Website of the National Archives of Australia. A wonderful resource.
http://museum.wa.gov.au/research/research-areas/history/sheridans-badges About Sheridan’s (of course!)
http://www.stokesbadges.com.au/about/ For Stokes and Sons.
http://acms.sl.nsw.gov.au/item/itemDetailPaged.aspx?itemID=404849 About convict buttons.
Other recommended vintage bloggers:
Australian Military Button Collectors