Hi robertaj,
His name was sometimes written COWL, COWELL, COWELS or COWLES. So perhaps you could broaden your search by using these names ..
Do you know what date he died and where he is buried. Would help in a search

* Thomas & Jane Cowl arrived into Hobart on the 'Caroline' on 2 Feb 1828
* Thomas & Jane Cowl had a son, John 'Robert' Robinson Cowl (was that Jane's maiden name?) born 29 Dec 1828 in Launceston but not registered until 1833. He married in 1851 to Elizabeth Hedington and had about 13 children and they were all written Cowl. He died in 1917
* In Aug 1835 Thomas Cowles was in Bothwell, Tasmania when he was fined 5s for drunkenness
* In the Launceston Advertiser of 8 Oct 1835 it has that Thomas Cowell obtained the license for the Jovial Carpenters, Launceston
* In janilye's list of 2015 it has that on 5 Oct 1836 Jane Cowl obtained the license for the next 12 months
* On 11 Oct 1838 the Hobart Town Courier listed Title Deeds from the Colonial Treasury:- Deeds of Grant in favour of the individuals whose names are hereunder mentioned are now ready to be issued on payment of the amount due thereon to the crown .. Thomas Cowl 1s 9d, Launceston (whatever that means)
* 7 month old Thomas Cowl died 3 Oct 1836 in Launceston and written as "the son of Thomas & Jane Cowl"

Publicans License Tasmania 1837 ]

Thomas Cowle Will

The Hobart Town Courier Fri 26 Feb 1836
WILLIAM THE FOURTH, by the Grace of
God, of the United Kingdom of Great Britain
and Ireland, King, Defender of the Faith.
In the administration of Thomas Cowle
late of Launceston, in Van Diemen's land,
licensed victualler, deceased,- to the next of
kin of the said Thomas Cowle, and all Chris-
tian people.
GREETING, -
YOU and each of you are hereby cited and
warned to be and appear in The Su-
preme Court of Van Diemen's land, at the Court-
house, Hobart town, on Monday the 14th day
of March now next ensuing, at 10 of the clock
in the fore-noon, then and there to show cause
why administration of the goods, chattels,
rights, credits, and effects of the said Thomas
Cowle, deceased, intestate, as hath been repre-
sented to us, should not be granted to Jane
Cowle, of Launceston aforesaid, widow of the
said Thomas Cowle.
Witness, the Honorable John Lewes Pedder,
esq. Chief Justice of the said Supreme Court at
Hobart town, aforesaid, the 19th day of
February, in the sixth year of our reign.
W. SORELL, Registrar.
John Ward Gleadow, Proctor for the said
Jane Cowle.
This is about all I can find at the moment, his name was sometimes, COWELL. In tas. index where I found the will there is 2 death certificates one is for a son also called Thomas. but I;ll leave you totry and sort it all out. janilye

thank you. It all helps.