A Corporal, doing what is expected, without being told...
an unfortunate rarity.
The following is from "The Private Soldier's and Militia Mens Friend", (pp.18-20) published in 1785 by a retired British Sergeant Major. It is chock full of excellent information, applicable to Bloodybacks and Yankee Doodles alike...
"FIRST you must provide yourself with a hand-vice, screwdrivers, rubbing sticks, and leather free from grease, oil, emery, crocus martis &c. The rubbing sticks for the arms should be made of deal wood of different sizes, with leather glued on them in the following manner:-Make the rubbing sticks very smooth and on one side of it lay the hot glue, and on this side your leather and press it down; then lay some glue on the leather and on that lay some emery, and press it a little into the glue, let them be well dried; with this use oil and an emery, brick dust, &c.; if you apply them properly by rubbing the arms well, they will give your arms a smooth surface: you are next to proceed to polish them; take crocus martis, and clean dry leather, rub the part which you want to polish until it is warm, when it will acquire a very fine dark gloss.
Brick Dust: Use old (pre-1930's)bricks. Newer bricks are harder and more abrasive.
Bricks must be free of mortar and crushed to a fine powder.
Remove any large, non-uniform pieces.
"The next thing I would advise you in to keep them clean when they are so, which you may easily do by paying proper attention to them in wet or damp weather; when you have done using them, take care to rub them dry by the fireside if possible. Take a quarter of an ounce of camphor, two ounces of hogs lard, melt them together; then add as much black lead as will turn it an iron colour. This composition laid on the iron parts for four and twenty hours, and then rubbed off, will prevent any iron from rusting for six months together.
Care and feeding: (l-r) crocus martis, hand vise, rubbing sticks, cartridge form,
oil flask, bee's wax, turn-screw, worm, pick/whisk, rosin, brick dust, tow and rags.
To clean the brass of your arms
"Take a little whiting or rotten stone, mix it with some spirits, lay it on the part you want to clean while wet, and with a piece of soft leather rub until the brasses are warm, and you will find it will give them a fine gloss. The buttons of your clothes should be cleaned with the same, only use a brush instead of leather.
"You ought to be very careful of the stock of your firelock to keep it from injury; and as the beauty of your stock very much assists the appearance of the barrel, the scratches, dents, holes, &c. should be filled up with bees-wax, and the part or whole stock when covered with bees-wax, should be varnished with black rosin, this will give it a fine dark gloss, and likewise preserve the wood."
 An abrasive similar to jeweler's rouge.
 Use old bricks (18thc) as modern bricks don't seem to reduce to the fine abrasive powder required.
 Mothballs-Camphor was and is a solid, formed from turpentine oils.
 Pipeclay, chalk? I find that plaster or chalk works well as a polish Similar to the chalky properties of modern brass cleaners or auto/metal rubbing or polishing compounds.
 Black rosin is available in cakes at music stores (for stringed instruments), and is pricey-or you can make your own by collecting rosin from pines and cooking it down-an experiment for another day!