Are we sure that this is rust? Last time I checked Aluminum doesn't rust...have you tried a chrome polish paste with a dremel (with a cloth adapter)?
Try soaking it in Kerosene for a while (Not that long..like 5 min), then rinse in Methyl Hydrate (brushing the residue off at each stage). Then try the chrome polish (I use Blue Magic) with a dremel at medium speed. Apply a small amount to the crank and also the cloth adapter.
Give it a shot...what do you have to loose? Try the crank first as this is the easiest part to attempt with.
John