I needed to re-attach the chrome bezel to my loop's speedo, and I decide to make a tool to do this. To re-attach the bezel, you first put some masking tape around its edge and then attach a (3-in) hose clamp around the outside of the bezel. Slip the tool over the hose clamp and tap it with a hammer to bend the edge of the bezel down.
The hose clamp keeps the working edge of the tool right on the part of the bezel you want to bend--it's just about impossible for the thing to slip. It worked great, the edge comes out quite even (I repositioned the hose clamp several times). Not perfect, but I'm very satisfied with the way it all worked out.
If anyone would like to borrow the tool, just let me know.