With my husband's family history I couldn't even verify a
marriage record in 1811 as the church was burned to the ground.
There are very few McKenna's 3 and McGuiness 2 in the British telephone book. Has complete addresses with postal codes.
Write letters and perhaps start an interest and they may help you find local materials. You can do this while waiting for a response on the message board.
Another alternative as most Irish 300 years later don't even know they had family that went to the New World is to
look for Memorial Inscriptions, how you tie them together I'm not sure without having a parish registers I don't know.
I have had 4 research trips to Ireland and never found the answers.
Anything is worth a try. Annette