The rear sight on my .54 flinter, is two steel pins, like sewing pins with little domes set with just the domes sticking up from the tang at the end of the barrel. The front sight is soldered on.
The 2 little domes, 1/8" apart make a really cool, almost invisible rear sight.
A conventional sight could also be dovetailed into the tang at the breech end of the barrel. That would keep dovetails away from the powder chamber area, if that was a consideration or goal.
That is what I did with the rear sight on the .45 cal. cap-lock barrel I also have for this pistol.