Land of the Lead has a set of one-page Napoleonics Rules. They’re designed for play with a “reinforced division” per side. Scroll down to the bottom of the page to find them.
napoleonics
The Immortal Memory
The Immortal Memory is a set of rule for refighting Trafalgar.
Le Baton Napoleonic Rules
Le Baton is a set of free wrgames rules for 15mm Napoleonics.
L’Orre Mixte Napoleonic Rules
L’Ordre Mixte is a Napoleonic Supplement to Fire and Fury.
Battle of Espinosa Free Board Game
Multiman Publishing offers a free board game of the Battle of Epinosa (Nov. 10 – 11, 1808).