Hello, I´m from Germany and Ive got a family tree. If you know where they started in Germany perhaps I can help you. My family tree looks back to Caspar Schelle born in 1620 in Peiting (Bavaria´). First named 1450 in Peiting in a so called Salbuch. Between 1517 and 1650 in Peiting Peter Schelle and Thomas Schelle.
Perhaps your William Schelle was one of this line.