Wow, thanks for all the offers, interest, and support! What a wonderful community we have here at Talk Bass. It's really something!
So I've been thinking about the taper. One concern is the control cavity. I had thought I might be able to just rout out an area from the output jack hole and use an oversized jack plate to avoid using a control cavity cover. But really, there's no reason to work that hard. Of course, if I use a control cavity cover, that may not play nice with a tapered body. So more thought is warranted on this matter.
Of course, looking through the pictures of the series, I'm not even seeing a cable between the bass and amp, and it seems she's not even using an amp most of the time. I don't even know if there's a jack plate or output jack on the cartoon version. I'm thinking a good place for the jack plate would be here:
She's playing left handed in this picture, so the bass is upside down. The controls also seem to move depending on which picture one looks at. But the final control positioning will determine where the control cavity cover ends up.
There's also the issue of fret lines. They're clearly not to scale in the pictures, and I will definitely need the lines. So my options are a maple fingerboard with laminate mahogany strips, a mahogany fingerboard with maple laminate strips, or in keeping with the picture, just drawing or painting black lines. I think in any of those options, I'd want to coat the fingerboard with epoxy - likely fiberglass resin as I have some from the acoustic build.
Regarding neck dive, I was thinking about putting a second spike on the upper horn, with a strap lock on top of it. But first I'll see how it balances. I really want to keep this as light as possible - I'll be walking around wearing it for hours at a time, over the course of a weekend. ouch.
And finally, I have to make a nut, I'll try making one from some of the scrap aluminum I have. The string spacing - well, that's another area of research. I never made a nut from scratch before.
Anyway, I'm off to cut some aluminum.