50th (Queen’s Own) Regiment of Foot
See also http://www.austbuttonhistory.com/uncategorized/2nd-april-2021/
In 1831 the British 50th Regiment of Foot was renamed ‘the Queen’s Own’ in honour of Queen Adelaide, wife of King William IV. The regiment served two terms in Australian colonies, from 1833-1841 then 1867-1869 (after fighting in New Zealand from late 1863). The 1855-1866 era full dress tunic above (courtesy National Army Museum https://collection.nam.ac.uk/detail.php?acc=1998-06-1-1) is like that worn during the second period in Australia. In 1881 the regiment was merged with the 97th to become the Queen’s Own Royal Kent Regiment.