I am descended from the same family, I think. If my records are correct, this is your great-grandfather's line:
Frank Percy D. (1898-1978) > John C. D. (1857-1945) > James D. (1816 - ? ) > Obadiah D. (1784-1862) > Isaac D. (1753-1847) > Obadiah D. (c,1720 - c.1797) > Josiah Davis(s)on (c.1692-c.1759) > Daniel Davison (c.1661-c.1702) > Daniel Davison (c. 1630-1693).
The Daniel who was son of Nicholas was English, and lived at Newbury, but is often confused with our Daniel, who was a Scot.
I would be very glad to get in touch and learn more about Obadiah & Polly (Webb) Davisson's descendants. Isaac Davisson came to Ohio with most of the family in 1808, but Obadiah was already married and they remained in West Virginia, but in their old age came back to South Charleston, Ohio. The only one of their children that I know about who also came to Ohio is the youngest daughter Selina (Davisson) Landaker, who predeceased her father. She still has descendants in Ohio. I have a record of eight daughters and a son James for Obadiah.