It is official, I'm old. Just can't seem to keep the sights and target clear enough in focus for any shots beyond fowler distance. Ive been looking for a period type of tang sight, but all I see are Lyman 57's and TC sights. Is anyone making period tang sights, or is this a do-it-yourself deal? If that is the case, can anyone recommend books or other sources? No, I do not want to move the present rear sight forward.