Here is a nice vintage Champion Blower & Forge Co.  USA made Die handle with a die in it.  It has a patent date of: DEC 7, 1894.  These die holders were made to each accept a certain size die and that die only.  The die size in this one is a 5/16"-18.  They are indexed in the holder with a reference tab.  Also note that the die is slightly adjustable with the flat head machine screw and the cone tapered nut.  The die is in good shape with no chipped teeth.  Also the die securing set screw turns freely and easily.   The die stock has a fixed guide built into the frame back side. The last set of photos show I cleaned the parts and you can see the parts and holder easier to understand how this works.  The 1 piece die handle is 13-1/2" long.  For reference the round die is about 1-1/2" in diameter in this size handle.  Rust free at over 120 years old is not bad!