What I've used to clean up rusty chrome, is an oxalic acid bath - It will remove the rust without affecting the chrome, or even paint (except red paint - turns it pink), as it only reacts with iron oxide (rust).
You can buy it easily in a store, as wood bleach, or just buy it in bulk - Pretty cheap, and it really works :
https://indianapolisvintage.proboards.com/thread/32/cleaning-chrome-oxalic-acid
You can buy it easily in a store, as wood bleach, or just buy it in bulk - Pretty cheap, and it really works :
https://indianapolisvintage.proboards.com/thread/32/cleaning-chrome-oxalic-acid