1:1 print as 1:144 scale model or depending on the 3D printer adjustment ratio, The positioning shaft can use a bamboo stick of appropriate size, Stl files do not need to be processed, just slice them directly. I made the mold parting for a FDM printer(render in blue). A resin-printed version is also available(render in yellow). Use blender3d to divide the model into small parts.(https://www.youtube.com/watch?v=4cvnNYGuRlA)