"”¦ He blows through his rifle to ascertain that it is clear, examines his flint, and thrusts a featther into the touch-hole. To a leatthern bag swung at his side is attached a powder-horn; his sheath-knife is there also; below hangs a narrow strip of homespun linen. He takes from his bag a bullet, pulls with his teeth the wooden stopper from his powder-horn, lays the ball in one hand, and with the other pours the powder upon it until it is just overtopped. Raising the horn to his mouth, he again closes it with the stopper, and restores it to its place. He introduces the powder into the tube; springs the box of his gun, greases the "patch" over with some melted tallow, or damps it; then places it on the honey-combed muzzle of his piece. The bullet is placed on the patch over the bore, and pressed with the handle of the knife, which now trims the edge of the linen. The elastic hickory rod, held with both hands, smoothly pushes the ball to its bed; once, twice, thrice has it rebounded. The rifle leaps as it were into the hunters arms, the feather is drawn from the touch-hole, the powder fills the pan, which is closed. “Now I’m ready,” cries the woodsman”¦."
yes they did cut patches at the muzzle even back when - how common is another question...this quote is from Audubon 1820's
The so-called patch knife is a late 19th/early 20th century term for the smaller bag knives, which IMO mostly came about when the frontier no longer was so wild and woolly. If you're a farmer or townsman out for a day of shooting smaller game such as squirrels or rabbits, in the more settled areas there was no real need for a larger or separate belt knife, and if the knife is attached to the shot bag one is ready to go by just grabbing your rifle and the bag with accoutrements the bare necessities attached.
Even less cumbersome would be for such a hunter a clasp knife of some sort, a day horn (which IMO most priming horns were in fact), and a bullet board with a few patched ball stuck in ones pocket - no real need even for a pouch and large horn to get a few squirrels for the table.