"what about a mission based on waterloo"A few problems with that . . .
First, the game sounds don't really lend themselves to a Napoleonic environment unless you have a great imagination ("Watkins, tke three men and cover the left with your muskets" becomes "3, 4, 5, 9 - go to Tree, nine o'clock").
Second, even the smallest Napoleonic battle had thousands of men on each side whereas OFP can handle at most only around 200 men per side. You can play Napoleonic skirmishes, but not battles.
Finally, until someone comes up with a good working horse the whole flavour of pre-WWI combat is imposible. From what I've read (and played) Napoleonic combat was all about infantry vs cavalry vs artillery vs infantry etc. Leave out the cavalry and you lose 90% of what made that period tick.
That being said, I am certain that someone, somewhere is working on solving all of these problems via OFP right this minute . . . ;D
Cheers
Roni