I'd leave it as it is Andy, it looks good enough to me for a simulated painted silver surface.
It's actually harder to achieve this effect than it is to do a bare metal finish. I usually use a regular silver paint, with a touch of white added to it. The use of gloss or matt white gives different effects. For example, my MiG 21 in the Cold War GB is supposed to be a silver dope coating, as applied to the real thing. This was made by the method above, where the amount of white added governs the final effect.