No real hurry. I have looked on the 1837 and (my scan on disc from Lib of Congr) 1856 LaTurret maps, the 1920 Marengo Soil Survey map, and a few others at the Cartography map site, all to no avail. It has occurred to me that "Moberly" might be the preception to a Kentuckyian's ear of Demopolis (de-MOP-er-lis) pronounced by Marengo county bondsmen.