Further to my note written a few hours ago. I've just looked at the FamilySearch Ancestral Record for John Gelling & Isabella Cavendish and I see this person has assigned their daughter Margaret to be the wife of John Faragher md 1824 Braddan. This is wrong. The 1854 will of John Gelling (bp 1764 md Elizabeth Oates 1787) mentions his daughter Margaret wife of John Faragher, and also lists several Faragher grandchildren.

Since he/she didn't get Margaret right, I don't trust the connection to the previous generation William Gelling & Catharine Cowley either. It might be right, but there are several other possibilities that could work just as well, such as:
1. son of Thomas Gelling & Isabella Craine 17 Mar 1765 St. Mathews Douglas
2. son of John Gelling & Mary Shimmin 25 May 1766 Kirk German
3. son of John Gelling & Margaret Caroon 8 Nov 1767 Braddan
4. son of William Gelling & Catharine Stevenson 24 Dec 1769 Braddan

The JG who married Elizabeth Walkinson in 1792 Braddan is probably one of these Johns.

If only we could get past this hurdle ....