Wow....that is interesting. I'm going to be in VA the end of this month. My intention is to take a day trip to Lexington to see some of the sites where my ancestors settled, and also to get my hands on a book at the archives at W & L that is about the McClures from Donnegla to Bottetourt.
Since Halbert and Agnes came from Donnegal this may shed some light on the story. Was James also from Donnegal? If these two are in fact brothers....their father was Arthur the wife of Arthur was listed as "Mrs. Andrew". Arthur supposedly died at sea around 1732. Would that work with the birthdate of James?
Halbert was born in 1685.
Thank you for your information.