I'd love to see Musket combat. I think M&B could handle musket combat quite well. I have 3 suggestions... (names in brackets mean those nations could be placed in IF more can be added to M&B)
The American War for Independence - 1770's - 80's
British (Hessian's) VS Americans (French)
Napoleonic Wars - 1780 - 1815
French (Spanish) VS British (Austrians, Dutch, Russians, Prussians)
American Civil War - Late 1800's
Union VS Confederates
I dint mind if the maps ain't realistic, I'd love to play as a British Rifleman