The Clucas name is in short supply in the north of the island and I suspect Thomas travelled.
The marriage in 1811 makes Margaret about 12 so her age may be suspect.
1851 in Lezayre has:-
Margaret Clucas 58 widow at Regaby
Janus? Dau. 35
James son 24
Daniel son 20
If this is the family it would make Margaret's age more acceptable.
Cath. Clucas ch 1813
Margaret Ann 1828
All christened in Andreas but Regaby is just inside the border with Lezayre and Bride.
Most appear to return to Andreas for burial and amongst them is a Thomas 1843 age 72 which may alter your perception.
There is an entry in the 1881 census under the name Margaret Allcus which I suspect is the wife of Thomas, with burial 1882 in Andreas.
An 1841 census look up for the family would be useful and would include Thomas and his origins.