I can find nothing on these folks, but do see where a George Brown was listed as a Pvt. in Co B of the 3rd Regt. O.V.I.Could it be that he served with Henry and this was why he served as a witness? Have you checked the death index at the Ohio Historical Center's online site?You might be able to find a death certificate for Susannah. If both Henry and Susannah were born before 1830. have you checked the 1830 census, looking for households with the names Brown and Talbott, searching for families that had children of the right age and sex to be Henry and Susannah?