Bits of progress on the design:
There are still (lots) more decaling details to work on, but it's starting to converge. I don't know yet if I'm satisfied with the front treatment, but it's not bad (?).
Right now my efforts are focused on figuring out whether I could actually build this thing.
For the helixes, I bought a sheet of overly-hard 1/16" balsa, and am going to try to create two-layer laminated pieces with it. That may be overkill, but they really seem like they'd be a likely candidate to break in any number of ways, so maybe a bit of overkill is not a bad idea. I went trolling around Home Depot today looking for a good 5.3" form to bend the helixes around, and found that 4" PVC couplers are awfully close at 5" in diameter. In the above pic I adjusted the diameter down to 5" and it looks fine, hardly able to tell the difference. I'll need to connect two of them together to achieve the desired lengh; a short piece of 4" pipe would be perfect, but I'm not gonna buy a 10 foot piece just to get 6". Will see if I can bum a piece of someone, else will improvise). My balsa bending experiments will commence soon. I have still not *totally* thrown away the idea of building them up from a bunch of small pieces and making them look pixelated like the sim image. But if I can get my stuff to bend properly I'll probably just do that.
I've also been staring at the open-air motor mount. It needs to be strong and also needs some decent motor retention strategy that will allow me to remove the motor without flexing the mount too much. I had a crazy thought of putting a retainer at the very back, and then making the whole darn assembly removable. But then, how would I attach it for flight? No idea yet. Must think hard about this. It looks cool (at least, without the motor in it), but if I can't make it solid and reliable then it's not worth it.
Finally, those rings are going to be a PITA. I'd probably need to cut them into three pieces and glue each piece in separately. That will not be enjoyable. I'm going to play around in OR and see if I can come up with a satisfactory design without them, but I suspect they'll stay because now I'm so used to them.