I had an SP1 and I removed the top guard from it. I used a razor and then sandpaper. The results were good, but it was a user so I wasn't after perfection. I'd guess the tang is thin compared to the handle, and that the handle is solid rubber. So, it should be okay to work on a bit, but I would go slow and not get carried away. It will behave differently than hard micarta, so I'm not sure a file will work well. Maybe a new razor blade and go slow. Good luck.