Have a 50 cal hopkins&allen black powder flintlock with brown barreled, rifled , stamped Spain model 29. In need of the inserts on the bottom of the barrel where the pins secure it through the stock or repaired. Replacement parts?? Age? I can't find any info on a mod 29 Hopkins and Allen or a parts list or diagram of this exact rifle. Any help would be great as well as what is it worth ? Is it worth repairing?