We don't see a lot of these rifles in Australia. I bought mine off a deceased estate about 12 years ago and it is a beautiful item to use. The action plate is 1873 but the breech block is marked 1884 which I assume is a factory refurbishment as it is now chambered for 45/70.
Recently I had a chance to show it to another collector and he commented on my rifle which is fitted with a "Buffington" rear sight. Both his rifles are fitted with a plain ladder sight.
So the question is, were these Buff sights fitted by the military or were they a aftermarket item for civilian target shooting.
https://i.imgur.com/QzZ2dMJ.jpg