[Steve D]

I clean my knobs with steel wool and Dawn, using a tooth brush to get the crud out of the grooves. This dulls the surface but gets all the dirt and oxidized plastic off. Next I buff the knob with tripoli on my buffing wheel staying away from any knurled or fluted areas and being careful not to press too hard which generates heat and could melt the plastic.

After polishing with a soft cloth to remove the buffing compound residue I wax the knob with carnauba wax. Did this technique on over 20 radios with excellent results:

http://galleries.shacknet.nu/steves/gall...que-Radios

Steve D