All - Thanks very much for the replies! Sorry for the meandering narrative. I’ll try to do better this time!
Hugh Ross of Borley is my 4th great grandfather. He has no birth record, no marriage record, and his first 3 children were born in 1755, 1759, and 1763 - all before 4 November 1764 when Rev. Thompson commenced his baptism register for Durness Parish. After that date Hugh Ross of Borley is visible as the father on six baptisms in the Durness registry - 1766, 1768, 1771, 1775, 1778, and 1781. Hugh’s wife Jean Manson of Borley is recorded on only one of the baptisms. The tablestone for their grave at Balnakeil provides their ages and dates of death, so we know them as Hugh (about 1755-1799) and Jean (about 1738-1831).
For John Ross, their first child, and a Quartermaster in the 71st Highlander Regiment of Foot, we have the memorial stone he erected at Balnakeil in honor of his parents, a grave stone at Inveresk from his brother officers honoring his 44 years of service in the army and noting his age at death and his death date in 1837, plus his entry on the local death registry, and his 4 page will filed in Edinburgh Sheriff Court. Therefore we have a high level of confidence in a birth for Quartermaster John Ross in Borley in 1755.
For Merran Ross, their second child, all we have is the memorial inscription about her short life (1759-1788) on the table stone at Balnakeil for Angus MacLeod and Janel Ross MacLeod.
For William Ross, their third child, we have circumstantial evidence for his birth in 1763, including the baptism in 1780 of the child he fathered as a single young lad in Borley. But the most important primary evidence is the will of QM John Ross in 1837, who directed Rev. Findlater to divide his estate in five equal shares "... to Donald Ross, now or lately residing at Pictou in Nova Scotia, John Ross residing at Boularderie Island of Cape Breton in North America, both my brothers, and to my sisters Barbara Ross, widow of the late Kenneth McCulloch residing in the Parish of Durness aforesaid and Janet Ross wife of Angus MacLeod farmer in the said Parish of Durness and Donald Ross my nephew son of the deceased William Ross my brother and found lately residing in the Isle of Hoan Parish of Durness aforesaid..."
Finally, we have this baptism in 1781: "Hugh Ross, alias MacEanmbicoun, tenent in Borley, and his wife Jean Manson, William, 13 July 1781"
I think this baptism is not a child, this is teenage William brought back to the congregation by his parents after his transgression the prior year for fathering a child as a "single young lad." There is a rich stream of evidence for the other siblings - Barbara (1768), Donald (1771), John (1775, my 3rd ggf), and Janet (1778), strong evidence of the first William, and no evidence of a second William.
In other words, two Johns, only one William, and hundreds of descendants.
Not to put too fine a point on it, but their descendants were a testament to the School at Loch Croisbol and the kind of citizens that emerged from Durness Parish - one grandson of Hugh and Jean was an MP in the first Canadian Parliament (1867-1874), and Minister of the Militia in the cabinet, and later a Senator in the Canadian Parliament (1905-1912). And a great-grandson of Hugh and Jean was Lieutenant Governor of the Province of Ontario, Canada (1927-1932). Both are in Wikipedia.
:-)