any idea what is different about a "Gemmer" sharps?
the foreword stock on mine comes off after removing 2 decorative slide pins.
i didn't notice that on a shiloh sharps i looked at.
I thought I said that: "He used factory actions but barrelled and stocked them in the same style as the Hawkens' well known muzzleloaders."
Piece by piece:
Gemmer put on an octagon barrel if the rifle did not come with one, like a Trapdoor Springfield.
He retained the foreend by a key or keys like a muzzleloader, as you mention, where Sharps used a screw and Springfield used bands.
He installed a barrel underrib and loops for a cleaning rod like a muzzleloader ramrod.
He put on a buttstock with a lot of drop and with a crescent buttplate, like a Hawken muzzleloader, where a Sharps came with either a military buttplate or a shotgun butt.
He often installed a patchbox and an iron pistol grip curl, again like a Hawken muzzleloader, where a breechloader did not much need a patchbox and was likely to have a plain straight grip or a true pistol grip.
He often used a buckhorn rear sight instead of the Sharps Lawrence patent sight.
I don't know how much of this stuff your Palmetto/Allen has, but I have seen it one time or another on Gemmers and reproductions. Probably some other things I don't remember. He would have put double set triggers on an Army surplus Trapdoor Springfield, for example.