What a surprise when I was able to find this jacket in military books as being 1815 Royal Mounted Artillery Gunner Jacket. So gorgeous with heavy cotton canvas, all that braiding, and so many antiqued brass semi-sphere buttons! Black (instead of dark blue) background with red collar,cuffs, flash trim, gold metallic flat trim at the neck, piping trim on front, sleeves and back, with folded epaulettes at the shoulders. Mens sizes. For the French and Dutch (so far, but just found another British reference) versions see the Napoleonic Hussars Jacket.
M – 42-44″ chest, L – 44-46″, XL – 46-48″. Top measurement is tightest with buttons closed.