Dave, the aperture attached as a new top lever screw was originally discussed by Oscar Gaddy on the old board, I think back in 2000 or 2001. Then, Clair Kofoed put up some specs and photos of the sight, I think on one of his drillings. It was an excellent post. I copied it but can't find it. Might it be archived? It would be well worth bringing it back. If not, perhaps Clair could bring it back. Mike Hensley