I have hit a brick wall tracing Patrick Carr.
Christopher Carr of Avondale, Thomastown, Co Dublin married Eliz McGuinness at Ballybrack R.C Church on 4 Feb 1872. They had a son James 1872-1874 and Patrick born 4 March 1875 at Thomastown. Elizabeth died in 1876.
In 1901 census Patrick is living at Patrick St DunLaoghaire with wife Teresa, married 18 Sept 1893. In 1911 census they are at 7 Pembroke Row, Dublin.
I feel Patrick was left with the McGuinness family in 1876. His father appears to have married again to Susan Farrell about 1878 (cant find where, maybe Liverpool as he was from there) they had seven further children whose details I know. I cannot find death of Patrick or Teresa. I don't think they had any children.