Well spotted, Len!
I think you are right about an error in the parish register. There are several baptism entries for children of Christopher Looney & Elizabeth Kneale in Maughold parish registers, but none for father Christopher Kneale apart from Archibald's entry:

Thomas Christopher Looney/Elizabeth Kneale 22 Nov 1815 Private baptism

Archibald Christopher Kneale/Elizabeth Kneale 11 Jan 1818

Elinor Christopher Looney/Elizabeth Kneale 12 Sep 1819

Jane Christopher Looney/I Kneale 21 Jan 1822 Private baptism

Cath Christopher Looney/Elizabeth Kneale 20 May 1824

Joseph Christopher Looney/Elizabeth Kneale 12 Apr 1826

Margaret Christopher Looney/Elizabeth Kneale 7 May 1828

Margaret Christopher Looney/Elizabeth Kneale 13 Feb 1831

John Christopher Looney/____ Kneale 18 Apr 1833

Christopher LOONEY aged 48 buried Maughold Dec 5 1834.

Elizabeth LOONEY aged 72, of Ballakilley, buried Maughold Nov 17 1866.

Christopher son of Patrick Looney and Cath Cowle bapt. 1 Oct 1786

Sue