prepping a sapphire burnisher

How hard is this to touch up with a eze-lap made with diamond?

What grit- eze lap would be appropriate? 1200 grit, 600, 400 240 120?

Michael,
What are you calling a sapphire burnisher? Can you describe it more and its use, not sure If you mean a carbide graver, a impregnated sapphire file type rod, or a burnisher for pivot polishing