Best finish for chain boxes/covers.
 

What I am looking for here is a stock clean un-restored look. I have bead blasted the covers, and lightly scuffed them, and they look pretty good, but after siting on my shelf for the last few months, they are beginning to oxidize. I I was thinking about a light coat of satin engine clear, but wondering if there is any type of alum treatment that would hold better for some time, and not change the appearance to much .
Would love to see some photos of what you have done. I am really trying to avoid the over-restored look here.

Powdercoat comes in clear, in various sheens.

Gibbs corrosion protection works very well for both Aluminum and Magnesium

Gibbs Brand Lubricant and Penetrating Oil all deep cleaner stops corrosion is a mechanics dream.

I've used a product called "SharkHide" with very good results. I believe Eastwood sells it now.