Another paint for plastic I will almost swear by is Krylon Fusion Spray Paint for plastic. If you follow their prep instructions it almost seems like that paint actually "bonds" to what you are painting.
I've used the Krylon fusion for a couple of projects to and it does work well, but did you want to still requires some prep work such as sanding, especially the joint ring. Cutting that down flush with the ball and sanding is usually what it takes. To get better access to the parts,
I've popped off the joints to cut and sand them. The paint has to be cured 24 hours before popping back in.
Once I think I'm done, I'm still dabbing on a touch of crazy glue applied with a tooth pick for a durable cover.
I bought this product from microscale industries, called Micro Flat.
I may give this stuff a try. The problem with crazy glue is that if it gets into the joint, you're screwed.