Restored many like this. Try buffing it out with 360 grit metallic sandpaper. I usually clamp it securely in the workstand and buff as I would a pair of good shoes. Once the "ruts" are gone, then buff with with 400 or 600 grit until smooth. Finally, polish it with Mother's Alum polish or similar brand, and you now have a really nice new-looking post.
>I have a bicycle where the seat post is scarred from being twisted back and
> forth and pushed into the frame. The seatpost was custom modified, with a
> Campagnolo head and a made to fit shaft. Consequently, I want to do what
> can to smooth it out. Are there any tips for restoring seat posts? This
> one wasn't anodized and doesn't need to be polished. It is made from
> aluminum. Thanks!
> Noah J. Gellner
> New York, NY USA