Here is the progress I've made so far using a wonderful product from Vintage Trailer Supply called Nuvite polishing compound.
Can't imagine what someone would charge to do it. I also found a nifty trick.
If you use Never Dull wadding polish ($4.87 )first and get the majority of the black off, then use your nuvite, you can get by alot cheaper with the same result.
Here is the link I used, free ship too! http://www.amazon.com/Eagle-One-1035605-Nevr-Dull-Wadding/dp/B000CNBI1A/ref=sr_1_12?ie=UTF8&qid=1375412956&sr=8-12&keywords=aluminum+polish