Your ancestor John Thomas was evidently one of the three witnesses to the will of John Gutridge, of Champaign County, Ohio (will dated 22 Jun 1822, probated 5 Jul 1824). I have been collecting Gutridge information for over 30 years. One of the little background stories I picked up on was this deposition of Christopher Stark Wood (1771-1855) in the Lyman C. Draper papers at the Wisconsin Historical Society:
Notes of Christopher Stark Wood
About 1786 David Thomas, a Welshman, commonly called Taff and one Smith were going after their horses in the cane break, near Washington (Ky.), in the fall of the year; Chris. Wood & James Gutridge, youths of 14 went out to cut cane and had horses to bring in the bundles to feed their horses locked up during the night. About sundown. Finally Wood said he had a singular fear come over him and he said he was afraid of Indians and would take his bundle and started back. Wood taking the lead a few rods soon passed Thomas & Smith and told them they saw their horse some 300 yards ahead; Cpt. Snake & some 3 other Indians, two on each side of the path--ran and grabbed them, Snake laughing when he took them. The Indians took their horses. Next morning early Snake told the whites, only two miles from Washington, they might go home & while Thomas was very polite, bowing, "Thank ye, good Indians, Thank ye good Indians" and moving away, Smith was contending for his horse--wouldn't go without--when Snake frowningly drew his tomahawk & made a motion & told him to be off quick & Smith was glad to decamp...Cpt. Snake has since told Judge Wood that he & his party would have taken him & Gutridge if they had not been too far apart, & found they could not get Gutridge, though could easily have got Wood. Snake laughed considerably over the affair when Wood told him he was the boy in front on the black horse!
It's possible that this David Thomas is related to your John -- the families that were in Washington County, Pennsylvania in the closing years of the Revolutionary War moved off to Mason County, Kentucky, and then, after the turn of the 19th century (around 1803-1807) moved across the Ohio River into Ohio.
We just have to keep digging on these poorly documented old families!
Big Rapids, Michigan