I hope some of the info helped you! I still have some things I want to check for you at the society! I can tell you, some of the properties are listed for this John MIlls, and are found in Preble county records, but are actually in Butler county after they split up the land again!
Oddly enough, does your Mills family go to Clark OCunty, Soringfield? My family has a Mills line, and it also happens to be the road that my grandfathers farm is on, and has been in the family for years and years(like 1800's sometime) Our surnames for the Mills line are Tuttles, Todds, Garloghs, Cultice! I do know there was a John Mills, and I thooght Abagail! Julie