Hi folks, hope this hasn't been asked a thousand times; I did a search but nothing useful came up. I have a Fender Jazz that's been my main instrument for 20 years and it's showing wear and tear like you might expect. The main problem is the neck. There's a big ding in the centre of the back of it, and on the G-string side around the C-fret just below the edge binding there's a rough bit where the varnish has worn away and it's down to the wood. I'm happy to take sander and paintbrush to it myself, but what varnish/lacquer/automotive product do you guys recommend I use to fill and protect? Thanks in anticipation, Doug.