sweet. can i see some pix?by bumps i mean the sandpaper like feel on the surface.

 

Then yes, you can sand those down. It'll take some patients but it can and has been done before. I'm doing it to my valve cover now (the polishing part...well, I've been doing it for a couple of months now, lol. It doesn't take that long, I've just been lazy to do it in a timely manner, plus I'm waiting on some hardware for it before I put it on my car.

Anyway, yes
...and yes...pics Scatpack!