There's enough facets on your model in the prior images that it should smooth away fine with the right smoothing angle. They're pretty simple shapes, so you shouldn't need a lot of geometry.
EDIT: Looking at it again, you've got enough facets that the surface should have looked smooth even with a 30º smoothing angle. Weird.
EDIT: Looking at it again, you've got enough facets that the surface should have looked smooth even with a 30º smoothing angle. Weird.