Another thing that I can across that might be helpful. There was a three way division of land belonging to the late Benjamin Twombly. The three were Isaac T. Demeritt, Betsey Demeritt (his sister), and Isaac Twombly.
There is nothing in the record that I have that indicates what relationship - if any - is between the Twomblys and Demeritts mentioned above.
Isaac's grandmother was Deborah Twombly b. 1766. I'm trying to determine who her parents were.