In order of most to least relevant:
Added little nubs to the outermost layer. When assembling, these will help align the otherwise very uniform 28-sided portions. On the first ring I made, the alignment was off by ~1mm and it made the fit impossibly tight.
Changed the detenter into a ratchet. It only spins counterclockwise, but the shallower bend should also spin easier. Rotating clockwise to a hard stop ensures alignment of the outer letters.
For personal preference, I changed the square drawer into a tube. Option for a friction fit solid tube or you can delete some of the innermost rings for a skeletonized tube. Skeleton tube would have to be glued to keep the layers aligned. Friction fit solid version only needs a few thin bars to add / remove a ring now!
Apologies for the lack of color on this sketch. I’ll colorize before I cut! Once I know the model works, I’ll clean it up to the standards of the original .svg so you can share.