I had my string guide for my bass pop out on the road; not having ideal tools, I tried repairing this, and the new screw I had broke off in the head stock. So I want my next attempt to repair this to be more successful, and not put too many more needless holes in. 1) The screw that goes into the head stock is fairly short. Is it worth putting a longer screw in, even going through the head? I'm worried this will risk cracking the head, but I want to be sure the next solution holds. 2) Is it worth trying to fill in the existing holes with plastic wood first? Or does it matter? Thank you!