I haven't been able to get in touch with Jean regarding the John Scott who is associated with Alexander. I've requested the record involved, which I believe was his will. Unfortunately, no one except Jean seems to know about it and she may still be recovering from her surgery.
There was a John Scott, merchant, of Mattox, Westmoreland County, Virginia whose will was proven in 1701, which corresponds with the individual mentioned by Jean. He mentions his sisters, Jane and Rebecca in Ireland; his brother, Gustavus, merchant in Bristol, lands in Virginia and Maryland, kinsman William Graham.
Another records says, John Bell, aged 37, testified that Mr. John Scott lived at the house of Mr. Robert Crawford, about a month before he went into Maryland about August 1703. In conversation with him, Mr. Scott stated that neither his brother, in Glasgow, Scotland nor anybody else should inherit his estate, but Mr. Robert Crawford- May 1705. This individual would seem more likely.
The mention of Maryland brings me back to Samuel Sinckler's will, which mentioned goods at the house of Matthew Steele. Matthew Steele was a merchant involved in trade in Virginia, Maryland, and Barbados, residing in Barbados until he appears to have moved to Westmoreland. It is interesting that he addresses John Waugh as his cousin. I'm not sure whether the two were connected by marriage in Virginia or before. However, a history of this Waugh family indicates that they were involved in Ireland and Glasgow.
Currently, I am looking into Baptist histories in Virginia, as the Sinklers were Baptisits by the time they arrived in Bedford County. I'm sure they are non- conformists in Stafford also, but not sure which kind. A branch of the Sinclair family from Caithness emigrated to Isle of Wight County where the first Baptist church was founded, according to various Baptist histories in Virginia. However, the do mention the early arrival of Baptists in Stafford, as early as, if not before, the Germanna settlement. It is important to note that the first Baptist church in Scotland is said to have been founded by William Sinclair in Caithness. I think that it is important to focus on the Glasgow and Stevenson sinclairs at this point, but to watch for connections to Caithness. Also, Issac Sinclair, grandson of Alexander, marries Letitia Douglas, daughter of Joseph Douglas, descendant of the Douglases of Mains, whose ancestor emigrated to Maryland from Glasgow in the tobacco trade. Another family to watch for.