1. Please give me your best procedure (since you figured it out).
2. I suggest you protect them ASAP. Please look at sharkhide.com They have a complete aluminum kit; i.e. cleaner, polish and protector. The results are stunning. Colin Hyde recommended it to me. He also knowns of a clear alodine process in Montreal.
I think a repair with a sharkhide protection will be better than a new part and way less expensive even with time spent and more durable.
Once again, nice work.