Carole, I had a look at the website you suggested and you are VERY knowledgeable about your Wisconsin and Michigan Finans.Those of us out here trying to help people who post queries have no way of knowing the knowledge level of the questioner.I would not have spent time researching and writing up a response to your post if I had any idea of your knowledge level.
I am descended from County Roscommon Finans, and I have little knowledge of Sligo Finans. (The Roscommon bunch keeps me busy enough).You didn't mention the Irish roots of your Finans within Sligo, but I will assume you are aware of the 19th century Tobercurry concentration, and the dearth of parish registers prior to the 1829 Catholic Emancipation Act.
I wish you good luck in your future Finan research. Email me if there is any way that I might be of help in the future. N.T.V.