The final result. You can see the epoxy collar in grey, that has been set around the yellow steel pipe. Strain gauges are embedded inside the moulding, and the tubes you can see carry strain data back to the surface (of the ocean). My mould had to seal around the large pipe and the small tubes, but still be removable after the epoxy sets.
Markings to assist with assembly. There are quite a few parts which all look similar (but are not), so a marking layer in the CAD makes life easy for the factory guys.
My Rhino model. The conical top and bottom of the mould is developable.