Hi,
well in my case I'm surely not going to paint on top of that helmet, If I wanted to paint one, I would buy a blank one, this is too expensive a piece to just repaint it!
Also, I would never paint on top of something with layered paint like this, you can already see all the layers, if you painted on top of that, that would just become a big mess.
In my case, I'm considering redoing a brand new ear and range finder with metal parts and decals and I might consider trying to improve the killstripes and trying to reshape the helmet a little bit, but apart from that I cannot do anything about the colors or the metallic effect.
cheers