I've had this guitar for about 10 years. I don't recall when exactly, but like 5 years ago-ish I noticed the back of the neck was quite discolored. Has anyone seen anything like this? I can't for the life of me figure out what happened to it? It's set right into the finish. Any thoughts? The neck is also slightly twisted. It doesn't affect the action too much but you can notice it when adjusting the truss rod. How could I get this repaired?