Ross Board and Scratchboard

Just got this message through the GNSI website. Normally I would not pass this on, but it might really be of interest to some of our members.

I'm a retired Certified Medical Illustrator and have a collection of authentic Ross Board for carbon dust and Ross Scratch Board for pen & ink for sale.
  If you know anyone who would want to buy sheets of the Ross Board, could you pass on this website address:

  I would like to see the sheets go to good illustrators to produce beautiful drawings.