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.
Warflag has some modifications for the commercial Age of Reason rules to allow you tu use them to fight battles in the Age of Marlborough.
The Perfect Captain offers the second edition of John Bull / Patriots, their rules set for game of the American Revolution and War of 1812. These are the most visually striking rules sets available today — either commercially or free. And these are FREE!
Seven Years Warmaster is an adaptation of Games Workshop’s Warmaster rules for the Seven Years War.
Tim’s Miniatures Blog has some Age of Sail House Rules for Savage Worlds. He also has some Savage criticism of those who wrote the Pirates of the Savage Main rules.