Hello Mike, I am revisiting your request for information on your family line and I can give you some information here:
Thosmas Costelloe was born in Loughill in 1856, I believe his parents were Patrick Costelloe and Maria Crinnane - who actually originated from Moyvane, (very near to Foynes) which comes into the Kerry diocese - however I think you might need to check this further , you could go to Roots.ie which will give you sall the parish records
Thomas maddired Bridget Magrath (born 1859) records are Jul-Sept 1880 Glin, Ireland Vol 5 pg 127 and file No. 101253 if you want to get a copy. Thoams was not able to write; but apparently lived a good and long life
Michael was born in 1891 and Patrick in 1916 Oct-Dec 1916 Vol5 pg 275 film No. 101076 Do take care though as there is 360 plus Costelloes in the Limerick area but concentrate on Foynes as Thomas was an agricultural worker there and they very often remain in the same locality I gather from a friend who knew the family well, that Michael was a miller (does this mean anything to you?)
When we are able to get and about I will visit my friend who will possibly be able to update me although he has told me that there is still a minor few of the family in the area.
So for now be patient again and I will come back to you in due course
Good Luck
Jennifer Jean contact:- killeedy1@irelandxo