I printed up the design as shown earlier. The new detent mechanism works pretty well, and is easier to dial in.
The potentiometer holder and gearing also works.

However, I decided that since I will be making the final 3D printed parts on Shapeways, I shouldn't limit my geometry to what an FDM machine can do. It can still be made on one, but will require a bit of extra cleanup.

One thing that was still bothering me was the center of mass sitting right over the feet, meaning almost any extra force on the lever will cause it to top over. So I added mass wherever possible in the way of four 1/8" steel ballast plates. These will sit on the inside of the housing. That way it is far less likely to tip over even in use. Plus it still has the magnets to provide a few pounds of force if placed on a steel surface.