Jumping in with possibly extraneous information...
I've been trying to trace the Ferris/Farris people in New Brunswick and Maine.
I suggest Martha Ford Barto's book "Passamaquoddy: Genealogies of the West Isles Families", specifically pages 73-77. You probably already know this but it might clear up some confusion with the Sunbury clan because i also find the names repetitive.
She also wrote "The Flagg Family of Grand Manan" but I don't remember if it lists any Ferris/Farris in it. I found it at
https://books.familysearch.orgGood luck,
Alice