Hello, I also descend from a William Guest (my 6th great gf) b. 1725 d. 1801 & Susannah Howard on my mother's side. I have found "another" Benjamin Franklin Guest to be their son b. 1757 in Virginia, d. 12/19/1841 in Alabama.
My GUEST family line continues from William > William, Jr. > Nathaniel Allen > Moses Holland > William Wesley > Joseph Lane > Minnie Pearl > Patricia Juanita (Holmes) > me (Cheryl Sanders).
Please feel free to contact me with any questions/information & look up my family tree (cheryl sanders SANDERS/HOLMES family tree). Perhaps we can help each other fill in the gaps.