I was looking at the Michigan County Marriages registry and there was a William Shanks and Jennie C. Best that were immediately after William Marshall and Mary Shanks. Do you have any information about William and Jennie? They are in my family line. It also listed a William Shanks as a witness at Mary's wedding.
Another question - this might be a stretch, but do you know of a Pat Shanks who is the daughter of Francis Monte Shanks and Dorothy Ruth McGlashan?