VPI Industries Isolation table (rare?)

Vpi isolation table.  Spring suspension with very heavy platter.  Platter is a sandwich of what looks to be mdf wood and 2 sheets of heavy steel. After doing some research, I've found Vpi isolation tables to be somewhat rare. Those I have found weigh in at about 10-12 lbs complete.  The platter alone on this unit weighs 25lbs!  I suspect this to be an early production unit from the late 70's and to be very rare.  Anyone with further knowledge, please let me (us) know.  Dimensions of platter are 19 3/8" x 15 3/4".  Exterior dimensions of supporting wood table are 21 5/16" x 17 5/8".  Overall condition of unit conservatively rated as good with a few minor scratches.  No major gouges or dents.  Wood finish would best be described as walnut.   Unit would make excellent isolation for a non suspended turntable or for a custom turntable build.  Carefully packed to ensure safe delivery.  Although new to selling on Audiogon, I do have a 100% feedback rating on Ebay.  You can see my feedback under seller rp1061.  Thanks for looking.