Phil, no - other than adding to my collection of Thomas Kelletts! They could be related - do you know where they lived or were born? - but I only know of my Thomas Kellett's daughter Frances Margaret. He could have had sons but I don't know.There is a good chance that he had a son named William Kellett who married my Gx3 aunt Eliza Hartley and emigrated to Australia in 1841.His father is recorded as being Thomas Kellett.
Eliza's brother John Hartley and his family, including his mother Frances Margaret Hartley [nee Kellett], elso emigrated to Australia in 1853.
Where did your Kelletts live in Ireland? Oldcastle or nearby? It would help to know.