A distant relative has drawn my attention to an old (1913) book on Moir family history that is able to be viewed online. It is Moir Genealogy and Collateral Lines by Alexander L Moir, and the relevant sections for the McNaughton family are pages 159 to 175.
These pages list descendants of James Moir, who was born in the later years of the 17th century, and includes the following descendants in a direct line:
George Moir (1702 or 1713 to 1784 – I still have to resolve his birth date)
George Moir (1746 to 1825)
George Moir (1790 to 1871)
Elspet Moir (1833 to 1891)
Some of the details are different to what I have found elsewhere, so I am still checking on that.
One of the most interesting parts of this section of the book are the photos after page 168. I am still checking some of the details, but a photo of George Moir (1790 – 1871) and his wife Margaret Calder (1792 – 1866), which you can see on George Moir’s page. I’ll be adding some of the other photos soon.
I’ve also added an old photo of the Methlick Parish church (1780-1867), which would have been the church many of the Moirs were familiar with.