I would definetly check the other county. Reason: you have no idea if John wrote the will long before county change or if he decided that, that was his county and did not care what the govt. said. Was he a young grandfather of older.You don't even know when he started to live there. Did he build or buy house etc. I really would check other counties close by property, because I have found material in other counties! Good luck in your search!
deedee