To polish micarta, usually a 400 grit sand job and a buffing is enough. If you don't have a buffer, go higher on the grits and then as a last step, oil the blade (WD40, mineral oil, whatever. I like mineral oil). Start with 400 grit paper to see if the scuffs disappear. Yes, use it wet. Micarta dust is bad for ya. Wear a mask fo some type, preferably a respirator. SOmetimes I liek to sand micarta under a tap with running water. That will help keep the dust down, and keeps the paper wet!
Good luck