I just re-did mine (the hook), it was in about the same state as yours if not a tad worse. I put it in a bath of Gelled Rust Remover from Dominion Sure Seal Ltd. Removes rust from chrome eliminates sanding an leaves a protective coating that eliminates further rust and prepares the surface for paint.
I let it soak for 24 hours (fully immersed), and wiped the gel away and then lightly wire brushed by hand and I was blown away by the results which to me was like new. I have used it as is. Actually installed it just last week.