Chris Kemp has a mini campaign for his Not Quite Mechanized rules.
rules
Battle of Britain Rules and Playing Pieces
The Battle of Britain is a complete strategic game for refighting the epic battle of 1940.
Pulp Action Miniatures Rules
Dadie Piombo has a set of basic rules for playing Pulp Action miniatures games.
Steve’s Horse and Musket Rules
Steve’s Horse and Musket Rules are designed to be a simple set of rules emphasizing the three arms (horse, foot, guns) and command.
American Civil War Riverine Actions
Mike Callan offers this set of free wargames rules for American Civil War Ironclads. The set originally was published in Wargames Illustrated 14.