Does Gibson's nitrocellulose paint yellow after time? Does nitro normally do this? I was told it does and I believe it, but I want to know if it will yellow to a vintage white or actually turn yellow. And also, I found some original tuners for my '68 SG Custom, however I have already reamed the headstock holes out for my new Grover Klusons. Better to keep the Grovers, or better to revert the headstock to the smaller holes and stick the originals in there? Thanks.