The plating is damaged. So any method of bringing them back to clean, bare steel will be. Required first step. Personally, unless you are going to replate them using a DIY electro plating method, I’d simply use some high heat spray paint or powder coat in a cast aluminum color and call it a day.
Short of a concours restoration, electro plating is a lot more trouble than it’s worth for a “rider” bike. Clean them, protect them, and enjoy the bike. Lots of other bikes to restore and ride…