I am aslo working on a Kilroy family tree. My Kilroys came to Manchester England from Ireland in circa 1823/1827.
John and his wife Catherine travelled with their two children John and Catherine both born 1822 in Ireland, they later had William,Michael and Mary. I believe John came to Manchester to work on the Bridgewater canal systems John became a chairmaker and settled in Angelmeadow which was the Irish section of Manchester.
I am not sure which part of Ireland they came from because as yet I have not located their migration to Manchester other than rough arithmetic working on the births of their children.
It would be lovely to hear how you are doing with your tree and hopefully to make a connection.
There are to this day many Kilroys living in the Manchester area of England.