Hey, I think your mouse looks pretty cool. I love the speckled egg shell look. It looks kind of like a Robin's Egg. I have some advice for you, if you're interested. If you're going to spray paint something like this, you can disassemble it first with a screwdriver. Take it apart and spray the case only. Same thing for keyboards, PCs, and anything else you can take apart fairly easily. Second, when you're spraying it, suspend it from a string or two, or support it by a single stick from below. Don't touch it until it's dry.

As for your current situation, buy a new identical mouse and transfer the working guts from the new one to your customized one.