Since the main problem is the rust stains, try some barkeeper's friend. Good for removing rust stains. It will turn the aluminum gray, but that can be polished out again with your metal polish. It's mainly oxalic acid, so don't leave it on too long or it will eat the aluminum and the rust. It will chemically react. Try a small area first.

I'd suggest avoiding any abrasive more coarse than a scouring kitchen sponge or some extra fine scotchbrite.

Autosol and similar polishes are not meant to be used that way, btw. It's a very fine polishing compound, not a chemical cleaner. Dip a rag in a bit of it and rub hard, then buff with a clean dry rag.