Bridgeport boring head.  Integral shank.  Short travel,
only about 5/8". Gross initial adjustment is made by tool (bar) 
choice or adjustment.  However, the especially large dial is 
easy to read as well as direct reading.  Meaning one increment 
on the dial equals 1/2 thousandth travel, or 1 thousandth off 
the diameter.  The tool shows abuse and unfortunately the shank 
is integral (not replaceable).  However,  for a single point tool, 
the "accuracy" of the shank is not critical as long as it is a 
rigid connection.