Shadowbox ends up having the same problem, how to attach it. Even JB is going to have a problem holding a pinball especially if you don't want the product to show. If you don't have a drill press handy (you'd also need a vise) I would start off by sanding down the back side (if there is such a thing) with some heavy grit sandpaper. Once you have a rough surface you can try JB weld or some other moldable epoxy, I don't think super glue will work.