Looks great to me.
Beside the gold (or is it a dark yellow??) what isn't correct. The second regiment of the Imperial Gard had yellow laces and shabracks.
For the horse: The Dutch Lancers (2nd Regiment) rode on chestnuts and bays and cost in that time 460 FF. So absolutely no Grey. They came from the regions Ardennes, Manceh, Orne and Calvados.
I think this is the picture where the customer had his idea.
He let the artistic freedom first before history accurecy. It's allowed for this time