Hi, I have some wood-framed copper-clad dormers. The copper is either 8 or 16 oz. copper. Currently there is no window in the window-holes. Here is a picture: http://rmihaly.home.mindspring.com/dormers/copper-dormer-windows.jpg I thought maybe I should just order some sealed, double-paned glass panels with which I'd fill the holes. Then I'd screw in molding to hold the sealed windows in place and put gobs and gobs silicon (or some kinda roof tar?) to waterproof. Do you have better advice for me?