Hi, What to do with your dome you can't resell because of rather severe scratches. Well hang it to the ceiling. This way you'll think of all the great dives you did everytime you look up. I sed the extension ring as the mounting device. Drilled two holes to get a stick of metal and the kind of hook-screw to apply to mount it. video from the result https://youtu.be/rEUaQ9l0eHM