Descendants of John Watson 1721 information wanted

An interesting document sent from Canada and an unfinished pencil drawing of God and the devil the artist went to America these were given to me by Miss M Millar

Where are there their descendants now, information please

The forearm of the devil was never finished as the boat was due to sail he promised to finish it when he came back, but it is understood he settled in California and joined the film industry.

Has anyone got photographs of the Golden Wedding mentioned in Calebs letter