If they are rusty, likely the chrome plating has worn through in spots.

I've used salt and lemon juice to clean the copper bottoms of my pans, but I think this would be too harsh for your chrome.

Something stinky like Brasso cleans chrome nicely, but won't get rid of the rust. I think there are some automotive chrome paints out there, but I've never used them. If you want to eliminate all the rust.. you might be looking at getting the bases replated ..

My guess is there are some more knowlegeable people than me here to answer your question..

if you post a picture it would be easier to tell what to use for your project...but...if they're just random and small spots of rust then you can try very fine steel wool to clean up some of the rust and then apply some 'rust to primer' to the areas...it will turn it black and you might want to test a small area first..it stains some metal black....(it will turn the areas that had rust into black spots but at least they won't be rusty)
if the steel wool doesn't work then there is a product that you can paint on that is supposed to 'stop' the rust..you apply then wash it off..but you will still need to apply something to those areas (rust to primer or a sealant) as the rust might still come back especially during humid seasons

re-chroming by a proffesional can get costly but if you treat those areas like I mentioned above then you can touch up anything that really stands out with some 'silver' or 'chrome' paint after the rust to primer is dry
just a thought....