Sorry, I don't think I can help you. I did find an O'Hare from Galway, from the town of Loughria (sic), but the dates didn't match. I thought it might provide a clue to origins in Ireland. Don't let the spelling put you off. My great uncle changed the spelling of his name to O'Heare when he came to the US. Said Americans couldn't pronounce Hehir, and besides he wanted to be "American". He also, I note, added the O'. Hehir is closer to the Gaelic original.