This is the kind of labor intensive job you should do yourself. For rust where you can get at easily, some steel wool, or a "SOS pad or fine emery cloth will do it. For inside, some extra coarse polishing compound, or coarse automotive valve lapping compound on either rolled cloth strips where you can pass through, or on Q-tips for the housing stops.

Once you've cleaned them up, be sure to wash them thoroughly then paint them with some touch up paint.

I'm sure you could get the LBS to do the job, and if you want to go that route be sure to do it immediately because they'll want work now, but won't as soon as things warm up this Spring, and the price will rise.