Hi Everybody, So I was wondering about wood fillers. What different types are out there? Should I use a specific type for a lighter wood or for a darker wood (Granadillo by the way). I'm really just looking for any type of input/help you guys can give. Secondly is there any reason I shouldn't use polyurethane as a finish for a solid body? Or is Nitrocellulose more preferable for some reason? Thirdly, anybody happen to know what kind of finish Rickenbacker uses on their fretboards? Thanks!