4th Regiment of Foot (King’s Own)
One of these designs may have been worn in Australia. See also http://www.austbuttonhistory.com/uncategorized/20th-october-2020/
The first detachment of the 4th arrived in December 1831 as guards for a shipment of convicts. They left for India during 1836-7. As with many regiments assigned to the tough conditions of the colonies (climate, boredom, rum, deprivation), there were intermittent problems with discipline.
The infamous William Buckley joined the 4th in 1799. After being convicted of theft, he was sent as a convict to Australia, where he escaped in 1803 from the failed settlement at Sorrento, Victoria and lived for 32 years with local aborigines. At that time his old regiment was stationed in the colonies.