"... I have a copy of the St. Louis Church book of records ..."
Many of the St. Louis Catholic Church (City of Fond du Lac, WI) records are very brief. I scanned through the church registers (FHL films) and found a baptism for my research - the whole page almost illegible and without given names for the infants. The record you cite would almost certainly be William James Daley (translated from badly spelled church Latin into English).
Are you willing to check your book "St. Louis Catholic Parish, Fond du Lac, Wisconsin: Repertoire of Baptisms, Marriages and Burials, 1850-1920." for any other baptisms referencing a James (Jacob in church Latin) or Maria Casey? - or any burial/death events for the Casey surname (1855-1890).
The book is found in a couple of library collections, including the WHS, but not available through inter-library loan 8-(
Thanks.