I messaged my friend last night and have not yet heard back from her - hopefully today.
The Thwaits family was originally in Clintonville but some moved on to Jay, Essex County, New York where there is now a large Thwaits population.
I was born and lived in Black Brook for a quite a few years before moving to the area of Peasleeville - now live in Jefferson County, New York.
I have a Thomas Sears in my family tree as his daughter married into the Ormsby family and somehow there is a marriage into the Eells family (some of my ancestors) along the line.
It's been hectic this week with Halloween and a book sale at the Watertown Library where I volunteer, but I will take a look later today and see if I can find my "Headstone Inscriptions of Clinton County," Volumes I and II - and see if I can find any of your early Sears families.The Peasleeville/Patent Cemetery is in Volume I and the Fairview Cemetery in AuSable Forks in in Volume II.
I am certain you are on the right track and I am hoping I can locate something which will prove that out.
I also have a quite a few pages of the 1900 and 1910 Federal Census for the Black Brook, Peru, Peasleeville, Schuyler Falls area printed and in a notebook.I will try to skim those this evening and see what turns up.