Yes, of course, Finn, Ontario was not a village but actually the parish of St. Finnans.
To your knowledge, were there many O'Neil's in this area? I contacted the parish priest who said that Mary's surname could have indeed been O'Neil even if she married an O'Neil but it seems unlikely to me.
May I ask what exactly is the reference to Mary Kerevan and Richard O'Neil in the St. Raphael book? Is Kerevan an Irish name? A misspelling of Kerrigan perhaps?
Thanks for your reply.