Hello Lois. For the last couple of years or so, I've been building a database of Gellings, so I'm always interested in adding more to it. I had Paul Gelling & Catharine Sayle and their 6 children but nothing since their arrival to the USA in 1827. I didn't know about daughter Catherine and her husband Robert Caley, so you have pointed out new information greatly appreciated.

The website says her Littleton 1907 obituary gave her birth as "December 12 1818" on the Isle of Man. This matches very well to the IGI baptism "Cathl Gelling 20 Dec 1818 Patrick IOM Parents: Paul Gelling & Cath Tayle" [sic; s/b "Sayle"]. So you certainly have the correct connection to the Isle of Man.

Re: Catharine Sayle's parents, the IGI has a baptism 17 Apr 1797 at Patrick for Cath SAYLE d/o John SAYLE & Cath KINLOW. It also has baptisms with the same parents for John in 1800 and Ann in 1801, but the 1807 one for Margaret (also John 1810 and Isabella 1813) has the mother as Cath KINLEY. There is a Kirk Rushen marriage 27 Feb 1796 of John SAYLE to Cath KINLEY. I suspect "Kinlow" should be "Kinley" as Kinlow isn't a Manx name at all. Your later note with the 1833 probate for Paul Gelling mentions both brother John Sayle and sister Ann Sayle (md William Watterson) as involved with guardianship of Paul G Jr who is now an orphan. This all fits together well to be the correct Sayle connections.

I also believe you are correct with the parents of Paul Gelling to be John GELLING and Ellinor SAYLE who married 26 Oct 1776 at Kirk Michael. Paul was the youngest of 10 children of this couple:
1. John bp 22 Dec 1776 Kirk Michael. He is one of my mystery people. Possibly the one who married Catharine COOEL 14 Aug 1803 Braddan, and at Cattle Market Street Douglas in 1841 and 1851 census's and buried 1854 Braddan age 77. Or could be the one who married Sage Ann THOMAS 20 Jun 1811 Patrick. Or ?
2. Ann bp 1 Aug 1779 Patrick. Married Robert GORRY 19 Jan 1802 Patrick. Issue. May match the burial of Ann Gorry, Patrick 15 Feb 1812.
3. Philip bp 27 Dec 1780 Patrick. Buried 7 Jul 1789.
4. Thomas bp 14 Jul 1782 Patrick. Fits reasonably to the Thomas GILLING of "Kirkpatrick Mann" in the British Army Records 1760-1913 on FindMyPast who joined 2 Mar 1805 age "20 years", served at Zealand and other places including Waterloo and severely wounded at Toulouse in 1814 and discharged 14 Feb 1819 age 33 being "worn out". His age in the Army Records is 3 years too low though. Not found in any census.
5. Catharine bp 2 Jan 1785 Patrick. Married James YOUNG 20 Oct 1810 Patrick. Issue.
6. Margaret bp 10 Feb 1787 Patrick. Nothing more known. You mentioned that she may have married William Kelly, who was one of the witnesses of the 1833 probate of Paul Gelling in Cuyahoga. I just found this marriage on the IGI, which I had missed before: Wm KELLY & Margaret GELLIN 1 Aug 1812 Patrick. Issue. So if this is the right person, they also came to the USA.
7. William bp 14 Feb & bur'd 13 Mar 1789 Patrick
8. James bp 20 Jun 1790 Patrick. Reasonable fit to the one who married Margaret TEARE 14 Mar 1819 Patrick. Issue. Was a Ag Lab & Fisherman at Glenmay Patrick and buried 10 Jun 1872, if he's the right one. Ages in census and at burial are high, so might not be the right James.
9. Robert bp 26 Nov 1792 Patrick and buried 23 Oct 1854 Patrick age 62. In 1841 census he's a Net Maker age 48 at Knockata Moor, Patrick. Can't find him in 1851.
10. Paul bp 25 Feb 1795. Md Catharine SAYLE 12 Oct 1817 Patrick. Issue. To USA 1827.

John Gelling Sr works well to be the one bp 28 Jan 1748/9 Kirk Michael, son of William GELLING & Mary LACE who married 15 Jun 1745 Kirk Michael, 7 children. Mary was buried 1780 in Kirk Michael and William 1792 in Patrick age 75. Both left wills.
William was bp 17 Apr 1717 Kirk Michael son of John GELLING & Mary QUAYLE (widow of Daniel LACE) who married 13 Apr 1707 Braddan. 5 children but only William survived infancy. John died 1738 and Mary 1744/45 both Kirk Michael. Both left wills.
I believe this latter John is son of John Gelling & Margaret Christian of Camlork, Braddan, and grandson of Paul Gelling of Camlork who died 20 Mar 1661/62.

Ellinor SAYLE (wife of John GELLING) was bp 21 Mar 1748/49 Kirk Michael, d/o John SAYLE & Joney CLARK. John Sayle left a 1776 will which mentions daughter Ellinor and also "John Gelling husb of Ellinor" in the 1780 acknowledgement.