I've fitted a set of these barrels for a shop here, I think they came from EAA? A real PITA, and the regulation of the 45 bbls was done with some goofy little spacers, cant remember exactly.(OK, just looked a the picture closer, and the little dodad at the muzzle is what I remember not working to well for regulation) I do remember the afore mentioned firing pin and primer concerns I had. I thought at the time that the hammer- guns left barrel would be a real suprise if an when the primer let go straight back in the face. Im not sure if those pins and bushings are gas check style or not? I think I would cut a gas relief channel in the breech face if there were any non-standard ammo experiments tried. some of the older double guns had a feature lke that.
I built a set of inserts from a couple of cheepy Numrich M-L tubes, chambered in 45/70, 24" long and turned excentric(bore off center) at the muzzle so I could regulate them before the extractor cuts were machined. It worked pretty good, regulated to 75yds, and resurrected and old Elsie with a set of wrung barrels. God it is heavy though. Still in the safe some where, havent had it out in Years..
