Start with soap an water, then a simple rag and vinegar do wonders for scrubbing layers of grim and brightening them up. No heat necessary. Are you sure it's chromium and not nickel?
Coleman did not use chrome. They are always nickel and with time it goes dull and does not always shine up well. You can use a polish like Autosol but it is very easy to polish the plating off and have brass showing through. Al's suggestion is prety good and might be best tried first before you get aggressive with a metal polish. So gentle polish only or you will be paying for re plating. ::Neil::
Al and Neil thanks for the info. Hope to have some time next weekend to start cleaning these. Will post some pics.
use limeaway with double ought steel wool dont leave it on very long rub it either with your hands or the double ought than rinse with cold water ;i use it all the time and sure does bring back the shine thou you might have to do it more than once ;hope this helps