I'm looking for possible long range sights for my Buffalo Classic. Any ideas? There are a variety of Springfield trapdoor sights, some Sharps sights, and some repros available, but I'm trying to find a ladder sight that has a notched leaf for 100 yards and the ladder folds up for ranges up to 600 yards. It would be best if the sight would fit the 1" apart drilled and tapped holes already above the chamber. A tang sight would require drilling and tapping the receiver for one screw hole and inletting, bedding the stock for the second screw hole.