Thomas Kerrigan and wife Catherine shown at 20 Ellen Street Cardiff 1871 census. Both born Ireland, They had a son who called himself John Kerwin 1881 census then John Harris 1891 census. John's wife went to the parish for poor relief 21 November 1873 and told the authorities that her husband John Curwin has gone to Ellen Street Cardiff to do an apprenticeship. John Curwin married Jane Hudson in 23 September 1968 in Bethnal Green and John said his father was Thomas Curwin. Their son Sidney John Curwin was born 20 March 1870 in Limehouse and he was was my grandfather.He married as Sidney John Kerrigan in 1902 in Poplar. I would love to know his father's birth name and his grandfather Thomas's history, There is a family rumour that "he had problems with the customs" but no one knows who the ""he" refers to.
Any help to further my research would be appreciated,