In 1977 I received the following from Janet Narasimham, who I had hired to do some research on my Gelling family.

"Lonan Deeds Oct 1777/50
William Kneale to Jane Gelling. This is a marriage contract between Daniel Kneale and his wife Joney Quine on behalf of their son William Kneale and John Gelling of Braddan and Catherine Gelling his wife on behalf of thier only daughter Jane."

Jane Kneale als Gelling died ca 1798 and this is an extract from her will:
"Episc will 16 May 1798 (#1) Lonan Jane Kneale al Gelling
Wm Kneale her eldest son
Son Danl Kneale
Dau Cathrine Scarffe als Kneale [note: she was the wife of James Scarffe, son of John Scarffe and Margaret Killip]
Son James Kneale & Ann Kneale her dau exec
Guardians of Ann Kneale: Robert Gelling & John Gelling"

So we have a William Kneale marrying Ann Killip 26 Feb 1778 and another William Kneale marrying Jane Gelling in October 1777, both in Lonan. As the Lonan baptisms usually don't list the mother, it's hard to tell them apart. These two Williams may be cousins.