Beyond the Saale is a set of campaign rules for the Seven Years War.
Gross Jagersdorf is a free board game of the August 30, 1757 battle between the Russians and Prussians in the Seven Years War.
Fr. Aelred Glidden offers a set of fast play rules for the Seven Years War. I miss reading his articles in the now lamented MWAN magazine.
Seven Years Warmaster is an adaptation of Games Workshop’s Warmaster rules for the Seven Years War.
Fast Play Rules For The Seven Years War is a set of free wagames rules for mid 18th century games.