There's a shop out here that does plastic media blasting. They use plastic beads and the surface is unharmed by the blasting process. You might search for a plastic media blaster near you. Go look at some finished pieces to see if you like the process before you commit to having your Darley blasted....if you haven't ruined it with some other blasting method already.
Once blasted, you'll then have the option of having it powder coated a satin clear to preserve the original aluminum color while sealing the rough surface, thus making it easier for Mrs. Easy to dust your signals when she's cleaning out your closet.
