If the Thomas MESSENGER we are seeking is this man
Thomas MessengerBIRTH 1831
DEATH 22 Feb 1910 (aged 78–79)
BURIAL Yankalilla Public Cemetery, Yankalilla, District Council of Yankalilla, South Australia,
then his death notice on TROVE says he was a colonist of 62 years which gives an arrival date of 1848 so perhaps he's the one living at Hulcote in 1841 with parents Richard and Martha
https://trove.nla.gov.au/newspaper/article/208013710MESSENGER.—On the 23nd February, at Alberton, suddenly, of heart failure, Thomas Messenger, aged 79 years, leaving a widow, 5 sons, 5 daughters, 51 grandchildren, 9 great-grandchildren.
Colonist of 62 years. Late of Woodville and Two Wells.
He's buried at Yanakilla with
Amy MESSENGER 1834-1913 and
Matilda Amelia Messenger Stock 1862–1891 so I assume it's the correct man.
Neil Todd (Reply #2) posted an 1848 immigration
MESSENGER Thomas arrived 1848-03-23 on David Malcolm from London 1847-12-21 v Plymouth [Source:6,20]
Judith
edit to add: Amy was still alive when he died so the time spent in the colony is quite likely to be correct.