The Maughold parish register reads:
Thomas Kelwy and Jane Blacke married 7 Sep 1659.

The spelling in the register for early baptisms was:
Evan son of Thomas Kellwie bapt 14 Jun 1660
Ewan KEALWEY Son of Tho: buried Oct 16 1660
[Unnamed] child of Thomas Kelwy bapt 24 Nov 1661
John son of Thomas Kealwey bapt 16 Oct 1663
William son of Thomas Kealwey bapt 29 Oct 1665
Thomas son of Thomas Kealwey bapt 2 Aug 1667
Robert son of Thomas Kelwin bapt 16 Mar 1669/70
Ann dau of Thomas Kelwey 30 Sep 1672
Margaret dau of Thomas Kelwy bapt 17 Jan 1674/75
Thomas KELWEY buried May 16 1685.

Jane dau of John Kelwey bapt 22 May 1687
Thomas son of John Kelwey bapt 19 Nov 1688
James son of John Kelwey bapt 6 Jun 1691
[Unnamed] child of John Kelwy bapt 25 Mar 1696.

After that it was mainly spelt "Kelwey" with the odd "Kelvie" & "Kelvey".
e.g.
James son of Thomas Kelvey & Catherine bapt 6 Apr 1745.
Thomas Kelvie and Elizabeth Cole alias Curghey married 16 Jul 1748.

I couldn't see a marriage of Kelvie/Kelwey etc. to Jon Looney in the Maughold church early records.

Sue