Funny, right now I have 1/2 a set in my garage, waiting for the cold weather to break so I can do the same thing.
Taking a close look at your original pictures, it looks like there is still some scratches and definitely the "imprints" from the bolts. To me, that indicates that you still have some sanding to do. I would recommend starting at 220 and working all the way up to 1000 or 1500.
Rather than sanding all the way up to 2000, I would try polishing at this point.
I had success using a 3" wool cutting wheel mounted on an electric drill
(I used TCP Global Brand 3" Mini Buffing and Polishing Pad Kit with 4 Pads, Backing Plate, and 1/4" Drill Adapter from Amazon)
The pad described as Coarse wool compounding pad was the most effective for bringing up the shine.
You'll be able to tell pretty quickly whether or not you can continue with polishing or need to sand at a high grit)
For a compound, I liked Flitz and Mothers Aluminum Mag polish, but it seemed to me that all the major brands worked about the same.
I recommend 3M automotive wet/ dry paper and wet sanding throughout the process, a little dish soap added to the warm water, and wiping the lips dry with a clean paper towel as you switch grits.
Hope this helps. I'll post this week if I come across some life-changing discoveries.
BTW, what are you doing with your nuts and bolts?
I also plan on painting my stock E3 steel wheels and they need sanding/prep. The wheel lathe will make easy work of it.
