Izojar--
I have one of those sights, I have not mounted it yet, the rear screw in the tang serves as the rear screw to hold the sight. As best as I can tell, the peep hole is about an inch and a quarter above the rear tang hole. I will put mine on a Investarm Hawken, I have to replace the front sight with something taller then the origional sight. I just bought the tang sight from Gun Parts Corp, it is unused, but old. They had a few left for $36 each. That is a bargan for a TC vernier tang sight so they will not last long. I can not focus on regular sights anymore, but peep sights still work OK. I am sure that I will have to drill the peep hole a little larger, it is very small.