Rafngard:
I agree with Detlef. The second one seems to have some old oxidation giving it that darker appearance. Personally I would not clean it any further--just oil it or put some silicone wax on it. If you wanted to take it back to bright steel you could use a mild abrasive in a blasting box or spend a few hours polishing it with progressively finer grit paper. But I think it looks fine as it is--just my personal preference.
Always good to see another Gopher State poster.
Ian.