My grandfather had a company called "Schmid Game Company". He created a game called "Stock Market" which he copyrighted in 1959. During this process he obtained two copies of the original Dec. 31, 1935 Monopoly game patent. They are both stamped with the attorneys stamp "HOWARD L. FISCHER" Patent Attorney Engineer, 911 Foshay Tower MINNEAPOLIS 2, MINNESOTA. They also have handwritten on them the patent number and "Darrow". My grandfather passed away quite a long time ago. My father passed away about 5 years ago and I found these in a box from his house. Any idea what the value of these would be and who might be interested in them?