These cables fit, but are too short. But, the ends are correct, so I'm going to cut off a couple ends, splice two together, and it should be long enough:
https://www.amazon.com/gp/product/B01IZAX8ZA
Since they arrived, I fired up the print on the Omnithrottle adapter, which is a mix of:
https://www.thingiverse.com/thing:5027171
and
https://www.thingiverse.com/thing:5170701
I went with the second body version because, as the author says, more people have M3 nuts than have M3 knurled inserts - this applies to me as well.
In the end:
1. I printed them out of PLA+.
2. The two printed pieces fit together via a tight enough interference fit (even after sanding, I used a vise to press them together) that no bolting is necessary. If they work loose, I'll just dribble a little acrylic solvent adhesive (SciTech weld-on is a personal favorite), but I doubt this will be necessary.
3. As mentioned above, the cables are too short - cutting and soldering is required.
4. The dimensions are slightly off - either the original models are wrong, or my printer is off, or they're compensating for a material with higher shrinkage (like ASA). Options are sanding for a precise fit (which is what I will do because they're printed) or increasing the body size slightly (to enlarge the holes) and shrinking the shaft size slightly (so it fits into the NXT base correctly - but then the screw holes might not line up with those in the base). Or you can sit there sanding and shaving for a couple of hours while watching a movie, which is what I plan to do.
It should all be put back together tonight and I'll post pictures if it's not too late after Arnold gets that pesky Predator.
