Wow that's a pretty heavy-duty joystick, looks like a mini meat tenderizing hammer!
If you can't sand blast it like the prior suggestion try carefully using a brass wire wheel on an angle grinder, or a brush if you don't have one of those.
As far as the artwork goes its one color and very simple, you may want to try figuring out a way to restencil it after repainting the panel, seems very doable even though I've never tried it myself. You might be able to get away with rebuilding the artwork on the computer and using it on one of those T-shirt silk screening kits except with more appropriate paint.