The Black Brunswickers were a volunteer force formed by Frederick William, Duke of Brunswick, in 1809. This regiment was made up of elite German gentlemen and was nicknamed ‘Death or Glory’ because of their unique death’s head hat badge and strong commitment to duty. They faced heavy losses at the battle of Quatre Bras, and at Waterloo in 1815.

The Sieg oder Tod! (Victory or Death!)
Most unit members wore black uniforms, but light infantrymen and uhlans wore green. The Black Brunswickers also had these silver skull badges on their hats.
The big question I needed to decide was do I build the force using the British or the Prussian lists. Both could be argued equally but in the end I decided on the British.
Some of the units easily have British equivalents. Going through them in turn:
The Brunswick artillery consisted of both a foot and horse battery so are a direct equivalent.

Foot Artillery

Horse Artillery
Doctors were the same across most countries, although the French were more organised.

There were no Heavy Cavalry or Highlanders in the Brunswick army so neither of these can be used.

The Leib Battalion would be classed as a Grenadier

Infantry were the basis of all Napoleonic armies. Bruswick forces had both light and line infantry that were uniformed the same but with the pom pom on the Shako reversed in colour.

A Junior Officer could be displayed mounted or on foot and with a Shako or hat.

Hussars
The Uhlans and Hussars match up easily with the Light Cavalryman category

Uhlans (lancers)
Marines and Native scouts did not exist in the Brunswick Corps.

The Occultist from the Silver Bayonet or even an old fashioned with model could be used.
The Brunswick corps had an Avant Garde that could be used as the rifleman.

Avant Garde Firing
Brunswick did not have a nay so no sailors can be used.
There is no evidence of designated Sappers in the Brunswick Corps, but I could be wrong. Despite this I will probably be using one!
Supernatural Investigators and Veteran Hunters exist within in Silver Bayonet Armies and could be used.
My sample army consists of:
Leader: +1 Melee, +1Health, =1 Courage. Medic and Hard to Put Down attributes. Breastplate, 2 pistols, Heavy Weapon, Holy Symbol’
Grenadier: Oil and Torches (15 RP)
Rifleman: Salt bag (18 RP)
Sapper: Oil and Torches (12 RP)
Occultist: Silver Shot (20 RP)
Infantrymen: Silver Shot (10 RP)
Infantrymen: Iron Shot (10 RP)
Doctor: Holy Symbol (10 RP)
I hope to finish these by Sunday for a planned game.
All of the illustrations are from the Silver Bayonet Section of North Star or Perry Miniature, both of which I can thoroughly recommend.