I still make mistakes Kirk, it's just part of the game.
Just have fun building. The first time I built a neck it came out great.
I was amazed. So take a chance. Rooster
Make sure you get your neck level with the playing surface of your box. Allow for pickup clearance if you include an electric pickup. I have a 2 string dutar that didn't quite get those measurements right, so we are compensating with a higher bridge and string trees at the tuner end of things. I'll post images once I get the improved, stronger bridge in place and can plunk out some songs. Somehow I ended up with a 21.75" scale rather than 25". No idea how that happened, but there are online calculators that allow for any scale length you can imagine. The build is fretless, but I will use bright tacks to indicate the major pentatonic notes.