Thank you for your reply John.
That is unfortunate a genealogist from Cork couldn't find the information you are looking for. While under the civil registration scheme births, marriages, and deaths were supposed to be recorded by the local registrar based upon information supplied to him, this did not happen in every case.
Do you think that Patrick Hannon may have been born in Tipperary or perhaps Waterford, or did the genealogist also eliminate the possibility of Patrick Hannon's birth taking place in these counties as well?
Best of Luck.