Hello Fred and Biff,
My maternal grandmother, Anna Maria Priore was born in Corletto and I have the Toce and Calabrese families in my family tree, but not in the late 1800's. I am familiar with the Stoppelli surname through my research, but haven't found a link to my lines yet.
I have all of the Corleto records on film at the FHC and would be happy to do lookups for you if you would like. There are records on line, but I am not sure if they are free to view. Biff or someone on this forum may have access to them.
Also, I am going to PM you a couple of email addresses of people who have been to Corletto, may know your family and would be happy to help in your planning your trip..