Problem - no figures and no time.
Answer - Paper.
So I found some top-down images of every unit at Waterloo on the Junior general site:
http://www.juniorgeneral.org/index.php/figure/figureList/topdowns#87
Just look for those labelled as "Battle of Waterloo".
I printed them all out (25 or so sheets of A4 and a full ink cartridge). Laminated and cut out.
Here is an idea of what they look like on the table:
Buildings are quick assemblies of those in Miniature Wargames 386. Not that well put together, but throw-away.
Next problem is rules. There are hundreds of elements, I want to play this in 2-3 hours with two players, so about 30% of real time. That means really simple quick rules.
I have written a one page set that I will try.