The mouth insert, I'm guessing like all Sideshow heads, shrank in differently than the head. Same thing happened with the Drake figure with his eye inserts. I removed it and cut it down. I also heated the head up and pushed the mouth more closed. I tried having it completely closed but the partial open I thought looked more like Burton. Put the teeh in and glued it into place. I also shot some flat clear over the head. Seemed to help the stock paint pop better. I will say that like many have said, the stock paint does look pretty good in hand. I shot a ton of pics but for some reason no matter what I did, I could capture what I see in hand. Tried all sorts of different lighting but the details just disappear in pictures. It's not 100% but I'm happy to have this figure on my shelf. Im still looking for a replacement body, as I want the tank top Burton look but the stock body has too narrow of shoulders. So for now, it's Jean jacket Jack.
Better pic of the head but still not what I see in hand.