Congratulations Dave.
     I have only seen one up close - one time.
     About 15 years ago I did get ahold of most ot the manuals from the heathkit
   manual replacement service, all except the es-600 function generator manual.
     I still have not found a reason it is called the HC-1. I just call it the
   Heath Electronic Analog Computer Model ES-400, because es-400 is the model for
   the cabinet kit.
     I have a magazine cover about the Heath Analog Computer at
   
http://www.cowardstereoview.com/analog/readlist.htm
   I've envious, Good Luck with it.
  --Doug Coward Poulsbo, WA
   The new home of the
   Analog Museum and History Center is
   
http://www.cowardstereoview.com/analog