The builder called it Chocolate Zebrawood, but I am fairly certain that is not the actual wood species. It seems to be similar to Rosewood in weight, density, and porosity. I honestly have no clue what the actual wood is, but I would definitely do more necks made from the same stuff. I am loading it with soaked-in Bore oil, then I'll watch it for a few weeks, and decide if it needs something more substantial, treatmentwise, for long-term durability. It feels awesome, and I would put it somewhere between Rosewood and Ebony in overall feel when gripping it.
Here are some shots in better light before the headstock was carved, and the frets installed: