Wow Chet, this is great. I'm enjoying watching your progress. I'm working through my first bass right now, just not brave enough to post a build log. Curious about what Matthew told you about the D neck. I'm getting ready to shape my neck and hadn't thought much about it being different. I just assumed I'd leave it a little big and trim it down if I needed to.
It's worth working out what the profile of the neck will be while it's still a rectangular block. It's very easy to get the back on the neck perfectly shaped while the sides are still parallel. The neck and fingerboard are the player's interface with the bass and are worth getting right.