I (Moshe Callen) research historical board games and compile the rules. I also modify existing public domain games. These types of games I normally leave as public domain games.
A practical note:
I don't at the moment have a good program for creating diagrams, unless one dares to call MSPaint "good" which I shan't. Rules should still be clear the way they're written but if one has questions, I can be GM'ed.