Hello Gill
I am sorry I have no details which I can link with your own. Possibly the John Corkill Baptised 20 Dec 1784 Maughold, may be your John William but I do not know.
Robert Corkill and Esther Looney married 28 Jan 1806 Maughold. They lived at Ballakilley. The Maughold connection is in the family until after 1900 when they moved to Douglas.
Karen