I am quite enamored of DRAGONATORs Toilet Paper Holder. It is a well-thought-out design. The special cylinders that don't need support material was an epiphany.

This set of models, solves a few issues.

All of the pieces are rotated correctly for proper printing.
They are all centered on the build plate.
I have added a long pin model that can replace the 30mm screws
Additional models have been added to yield two parts with one print