Jlb43, which ones do you have? The Texas Paterson - gold plated, engraved, cased with spare cylinder, powder charger, circular capper combination tool and cleaning rod was made by Pedersoli. Some of the others were made from Uberti, Colt's, and Pietta parts sets.
The Sam Walker in the pictures was made by the Williamsburg Firearms Manufactory using Uberti parts. That's the reason there are no Italian proof marks or other manufacturers marks. There was also the Virginia Firearms Manufactory that made some of these commemoratives. Their makers mark is the Crown over V.
America Remembers is the successor company to the US Historical Society, and the American Historical Fondation. You can email America Remembers (marketing@americaremembers.com] and see if they still have brochures and information on the sets you have.