In those days everybody was trying to reuse the huge stocks of obsolete muzzleoaders. The closest I've seen is the Wanzl or krinka (sp). Most just copied the snider. If anyone would have altered us made muskets to the allen system in any quantity they should have been listed in the "arms of the world 1911 alfa" catalog or in Bannermans catalogs. Never seen one listed altho the alfa catalog offered us muskets in percussion and apparently "reverse enginneered" to flint. Both the alfa and the bannermans catalogs have been reproduced and are available. I like them as reference.