This part is meant to be printed in 2 halves (base → top) that are printed consecutively one on top of each other. Otherwise if you can't/won't bother to do this, the two parts can be glued together.
IMPORTANT: If you opted for printing consecutively one on top of each other the two parts, THE TOP GCODE MUST BE OFFSETED BY THE BASE HEIGHT which should be 5.25 mm.
During the creation of this project I stumbled on a bug:
In CURA (I don't know if other slicers do the same) trying to offset an .stl sliced in vase mode doesn't work as expected:

For this reason I created a decent tool that can offset on a wanted axis a GCODE for an amount of millimeters.
Everything is explained better in the GitHub repository that I created, including the source code!
The author marked this model as their own original creation.