I have a vintage bike with really bad rims. Rust, dirt etc.

I was wonder the following

1) How do i determine the metal(s) that these are made off?
2) Can i soak these in an oxalic acid bath?
3) Does the product Metal Rescue work? Might want to try this but at $25 a gallon this seems too costly?
4) Are there any other product(s) that will work for this?
5) How close to new looking can i get these just with good old rubbing compound and steel wool?

Any help would be appreciated.