Brian, here are a couple of interesting paragraphs from:
The Book of the Pistol and Revolver by Hugh B. C. Pollard
"The principle of ignition by percussion attracted universal attention, and gunsmiths in all parts of the world turned their attention to the matter. The result was a series of devices—detonating pellets, tubes, pastilles, and paper caps, as used in toy pistols to-day, or in connected tapes or strings for special primers. All were tried and abandoned in favor of the copper percussion cap, which many makers claim to have invented. Colonel Hawker claims it for Joseph Manton; Mr. Walker, of Philadelphia, has a good right to it! Egg also claimed it, as did many other makers of renown, but by 1815 the copper cap was in limited use on high-class private arms."
"At this time, too, the saw-handle dueling pistol came into favor, but this type of handle, in which the shape was exactly like a tenon saw, was not popular for other uses. I have seen a small pair of all-metal saw-handle pieces with belt hangers and stirrup ramrods by Manton—not Joe Manton, but his successors; but these were probably a special order executed possibly for an officer of the East India Company, as the style was similar to weapons popular in the Indies."