Hello Steve,
This is the information provided by the pump's manufacturer. "In January 1989, Hydromatic was purchased by the Aurora Pump Company, a unit of General Signal. Along with the acquisitions of Fairbanks Morse and Layne Bowler, this formed the General Signal Pump Group. This union lasted until August 1998 when the General Signal Pump Group was purchased by Pentair, Inc. out of St. Paul, Minnesota, USA. "