I've come into possession of an old guitar with a rosewood fretboard that has lots of scratches in it. I've cleaned up gunky boards before, but this will need more TLC than those. I want to smooth it out and make it look new again. Maybe it's just a simple as sanding between the frets with progressively finer and finer sandpaper, but I've seen so many different techniques for various things posted around here that I thought I'd ask for some thoughts. Never know when you can learn something new. Thanks!