I've painted two test figures for the cavalry I recently received from Old Glory UK. These are a light dragoon in a shako, and a dragoon/dragoon guard in a helmet.
The light dragoon is painted as a member of the 12th light dragoons for Waterloo. These were in the 4th British Cavalry Brigade at Waterloo. The regiment was three squadrons strong with around 430 sabres.
The dragoon is painted as the 6th dragoons (Inniskilling) who fought in the 2nd British Cavalry (Union) Brigade. The regiment started the day as the strongest of seven British heavy cavalry regiments with over 450 sabres in three squadrons.