While not set in the Napoleonic era, I have thought about using the Alternate History as written by Greg Keyes in his The Age of Unreason series.
The story spans the late seventeenth and early eighteenth century. The author makes use of pseudosciences (scientific alchemy instead of our physics) that were popular at the time: using affinity and aether, for example. Some historical characters appear: Isaac Newton, Louis XIV of France, Benjamin Franklin, Peter the Great of Russia and Blackbeard have important roles in various volumes. Action moves between England and France, later involving Russia, Austria and the American Colonies.
The story spans the late seventeenth and early eighteenth century. The author makes use of pseudosciences (scientific alchemy instead of our physics) that were popular at the time: using affinity and aether, for example. Some historical characters appear: Isaac Newton, Louis XIV of France, Benjamin Franklin, Peter the Great of Russia and Blackbeard have important roles in various volumes. Action moves between England and France, later involving Russia, Austria and the American Colonies.