This joint is used in modern guitars to achieve the strings break angle over the nut while conserving wood. Toothpick dowels are used to maintain position while clamping.
I’m using curly koa and herringbone purfling to trim out my redwood and Oregon myrtle OM.
A few years ago I cut this tree down to make more light in my kitchen. I have built one guitar with this wood and hope to make many more. But there’s too much here for me. Let me know if you’re interested.