Per the Ihere is a Thomas Benjaman (sic) Kermode christened at St. Matthews Douglas on August 13 1818. Parents are John Kermode and Elizabeth Harrison. This is a transcription from a parish record.
They married in Braddan on August 29 1816.
The 1841 census in Douglas has a John & Elizabth Kermode (District 7 Page 35 Entry 176), age given for both is 40. In 1841 ages were rounded down to the next 5. So 40 means between 40 & 44.
There is no obvious Thomas in Douglas in the 1841 census.