The second witness to the marriage of Nicholas and Elinor Kelly on 12 February 1788 at Kirk German was "William Cowley of the Close" - from my personal transcription of the Kk German Marriage reg befor 1820 it is almost unknown (I don't think more than once or twice) for a close family member to act as witness - It is possible that Nicholas Cowley was son of William Cowley & Elizabeth Crellin baptised Kirk Michael 2 April 1758. (the transcription of the Kk Michael registers is totally fouled up in the IGI being split between many 'patron submitted' pages - however there is a patron submitted entry William Cowley son of William C & Bessy (Elizabeth) Crellin about 1749 KK Mic bur 8 Nov 1833 - I can't find any obvious confirmatory evidence for this - note the 'about' ie they are guessing based on on other evidence - presumeably the burial - if so then this cannot be Illaim y close as he was reported as dying 1848 (I think actually 1849) - Rosser who wrote the history of Wesleyan Methodism has a one line statement 'useful local preacher' but he gave a reasonably full biography of deceased notable LP's which implies to me that William was still alive c. 1847/8 when the book was being written (and ties in with the account) - I think he was buried Braddan 30 Jan 1849 age 70.

If Charles was an active Methodist (or at least 'an earnest seeker after the truth' etc it is likely that he would be friendly with William (who might well be a relative but I havn't tried to follow his line)
It may be that wills could provide a better linkage - there is one for Nicholas Cowley German 1833 - however I can no longer access Brian Lawson's pages as he now appears to have added tracking cookies and they return 404 errors