Buffalo Arms Co also sold the Smith sights, they may have some in stock.
I have the 1895 sight, it is not a buckhorn, it's pretty flat across the sight leaf, what I prefer.
Mine is on an 1895 Cowboy. I bought a Marbles 31W front sight to zero the gun at 50 yards for BP deer hunting. The factory sight on the Cowboy is the 50W (.5" high) and would probably have you shooting quite low with the leaf sight.
Be cautious about buying old Smith 1895 ladder sights. I had one and sent it back for a retrofit after they adopted some changes.
1. The sight of 5-6 years ago had no ladder markings. None, you had to count clicks of elevation with that ball detent or use a dial caliper to check elevation setting for long range target work.
2. The notch in the ladder elevator was cut way too deep. This gave a good flip up sight setting for 100-125 yards, but when you raised the sight for 200 yard work, so much light came from under the ladder sight notch that you would lose the rear sight picture. They reduced the depth of the notch cut and now have a much better sight picture. One drawback is the ladder's lowest setting now puts you about 4-6' high at 100 yards.