Awesome idea. Looks great in my office / lab at home.
I printed the "no support" version and let my slicer add supports as needed. I tried printing the nubbin with the hole aligned vertically (rotated 90 degrees from the STL orientation) but had adhesion problems. Printed it as oriented (with supports) and it worked fine.
As you can see, I did mine in grey and black. I think it looks best with the "face" of the blade "out" in the "on" position. That's when you have the most light and are most likely to closely look at it.
One suggestion (I'm sure other's have made as well) is to create a 'split' version of the blade so that both the 'front' and 'back' are rounded and look identical. A bit of superglue or acetone would hook them together permanently.
Another option would be to make the round 'handle' bit on the top of the blade a separate part that is glued on. Then it could be printed "standing" (perpendicular to the build plate) so it can be completely round.
grey & black