1991 560SEL brake job; the saga continues....

[qualified-merc]

OK, after tearing through my parts supply, I finally figured out that I have already put new brake rotors on the 1991 Mercedes 560SEL. I figured it out because I have the OLD rotors lying under the work bench in the garage, go figure, right?

So....there is some surface rust that has developed on the new brake rotors that are on the car. I am thinking of using the Kent method using an abrasive pad attachment for an electric drill. Question; is there anything I can put on the brake rotors to help stop rust?