Hi Martin,
I don't know whether I've been looking in the wrong places ... but I can't figure out whether the 4th Light Dragoons were at Waterloo?
My 3xgt grandfather, James Dixon - possibly James John, or John James - (b. "St Andrew, London" on 1841 Census, which gives his birth at around 1790), was an officer with the 4th, and there's a problem with the date he became an officer (1809 or 1819?) . Therefore I have no idea whether he was even old enough to have been at this battle.
Any sign of him in your lists?
Cheers, Deb