Hi Steven. Can't prove it yet, but dates, places and names indicate the probable connection :Your Marston/Mastin ( gen #1)may well be the brother of Betsey (1791) and Nancy (1797) and the son of Oliver . Oliver was in Saratoga NY census in 1800 and 1810(dates are right for these siblings and location) Oliver was in Chenango Co as were Nancy, Betsey and Mastin in 1830 census. The three all went to Jones county, Iowa approx. same time and settled in the Anamosa-Langworthy area. I descend from Nancy who came to Anamosa area with husband Amasa Harvey & children in 1847 from Pitcher NY. In analysis of children counted in 1800 and 1810 Saratoga co. census, only Oliver could be father of Nancy and Betsey.......and probably Mastin.It was a large family. I just offer this for your consideration, not as anything in concrete.