Cimmaron is primarily an importer of Uberti firearms. However, the Uberti manufactures guns to Cimmaron specifications, and usually a Cimmaroon designed part will be included. A Cimmaron revolver is a better more refined or stronger gun than otherwise made by Uberti.
So, Uberti revolvers are "custom" made to Cimmarron standards. Other importers simply sell and ship.