This is a very nice original parts book for the JI Case 20 bar threshing machines.  It is fresh from an old Case dealership where it lived high and dry for decades.  It is in excellent condition with very minor handling wear and discoloration.  It measures about 9 x 12 inches with 114 pages. It is heavily illustrated with all of the parts including part numbers and would be a great addition to your early agricultural library especially if you have a Case threshing machine.  The pictures tell the story.  I can be reached at 262 573 193 1 if you'd like to talk about it.  Good Luck.