I know scarf joints are tough, but you should be able to do something more like a 20 degree cut by eye-ball and use a file to clean up the surfaces so they will mate right. Other than this 45 degree scarf joint, it looks like a great CBG, especially if it's only the second one you ever made. Also, I have been using a fret 0 (use same fret material as your other frets, but positioned where the nut should be), then I've been using a right sized screw in front of it to help position the strings and guide them to their respective tuning machines. I feel it makes the instrument sound better, especially when you compare the sound of an open string, to the sound of the same string fretted and disregarding the difference in the sound of the notes. It also helps with intonation of the instrument, especially for fret 1. These intonation problems come from not having the right height nut, or the string slots in the nut are not right on. This is a simple work around those issues.
Comments
I know scarf joints are tough, but you should be able to do something more like a 20 degree cut by eye-ball and use a file to clean up the surfaces so they will mate right. Other than this 45 degree scarf joint, it looks like a great CBG, especially if it's only the second one you ever made. Also, I have been using a fret 0 (use same fret material as your other frets, but positioned where the nut should be), then I've been using a right sized screw in front of it to help position the strings and guide them to their respective tuning machines. I feel it makes the instrument sound better, especially when you compare the sound of an open string, to the sound of the same string fretted and disregarding the difference in the sound of the notes. It also helps with intonation of the instrument, especially for fret 1. These intonation problems come from not having the right height nut, or the string slots in the nut are not right on. This is a simple work around those issues.
-Rand.