Thanks for all the help.
I have his wife (Bridget/Brigid Devine) side all sorted back multiple generations.
All his children have been accounted for.
Joseph, Ellen, Margaret, Mary Elizabeth, John, William, Brendan C, Kathleen and James.
Unfortunately I can’t find him in the 1903 census - there seemed to a lot of John Farrell’s who also have the same father ‘John Farrell’.