Hi -- I looked at your blog, which explained oxidizing with liver of sulfur, and I was looking for the follow-up article you mentioned about tumble polishing. Thanks!
Rio Grande has a video on how to antique with Liver of Sulfur, then use a tumbling machines to highlight the peaces and put a bright finish on the surface.
In the meantime, use some pumace powder or fine steel wool to remove the black from the high points. Tumble the silver in metal shot with 20 mule team borax and a drop of soap. I usually tumble for a couple of hours to get a great shine. Dry well so it wont tarnish right away.