The area around the grip is discolered but it's not wear. It's a build up of oils from your hands and from mainteance on your carbine. You can remove most of it with a good furniture stripper. Then you can apply the coating that you want to. With a shine to the frinish it makes me thing it might be Tung oil that was used on it.

I do hope you didn't drill any holes in your stock to mount the night vision equipment as your stock is a type 2 highwood which would not be the right one for the scope system but would be in demand for a mid production type carbine. But it does look nice for sure.