My new Luger

[Sticker]

Hi gang

Here are some pixs of my new Swiss Luger.

I have one little problem

You can see a light brown smudge on the grip. I figured it was just dirt so I went at it with a drop of water, a toothpick and a toothbrush. To my surprise it's not dirt, it's the plastic (phenolic?) fraying. So I don't think it can be removed, how would I hide it?

Sticker