Well, I seem to have made it. There were a few hurdles:
Problem: The loft tool added non-tangential splits. I am going to report this as a bug/seriously-needs-enhancement. If loft needs to split a surface, then the surface should be of nice quality. I probably should have merged all the split edges from the dummy match before rejoining to the real surfaces. Sigh.
Solution: Use Sweep-2, with the chain option chain to create the problem surface using dummy surface for tangent targets.(image below is the inner, made the same, though.)
Problem. The first half fin would not fillet because the joining surfaces tapered at too narrow of an angle. I’ve seen this kind of thing before.
Solution: For the short fins, make the ends of them more perpendicular to the body of the part, by making them a little stouter.
Possible Problem: The fill area in the belly of the thing, I did not trust the edge-curve created planar surface. Anytime, I join a revolved surface that creates a face at 90-degrees, I stress over it.
Possible Solution: Revolve out the crotch-like surface to include the missing panel–though, this means that the surface cannot be surf-matched, though again, it’s under a fin, so it’s okay. I tried to shrink it, but thinking about it, it’s trimmed, and that’s all there is to it.
Finished part and hull, showing the single-surface 2-1 adapter surface, and trimmed-revolved crotch area. LOL!
Dummy surfaces and profile curves. I set the Sweep2 settings to almost ignore the profile curves by loosening the Refit Cross Sections to a large number.
Victory-lap, or pathetic need for reassurance. Something like this…
It’s strange designing something heat-related like this. I want a large temperature difference between one leg and another–and from one end to another. So, it’s strange, if I put too much fillet on the fins, it works worse because I want the area between to act as a heat-break, as much as possible. It looks like an old power-line insulator, made of metal.