The jazz neck on the kiloton and sb basses is pretty thick front to back making it more substantial than you might be expecting, it's about the same Feel as my 83 L2000 flat 1 5/8 nut neck just narrower and thickerExactly... Custom. Your picture from the meetup gave me the GAS as this is what I'm looking to build ish. Still trying to decide if a Jazz nut width is something I can live with long term. Need to take the Black Eagle to practice and try it out more. I'm so used to the ATK700 neck now. But this is between a P and J nut profile.