Back then, for the P-51, we'd planned on building up a mould, using timber formers and plywood discs, covered in plaster, then moudling the spinner in glass fibre.
We chose a 'B' or 'C' model as we reckoned such areas as the canopy would be much easier to fabricate, being shallower curves and panels, compared to a 'D' variant. Plus, we both preferred the look of the 'razorback', compared to the 'D'.
For your Hurricane spinner, if you decide not to mould it yourself, you could probably obtain one from somewhere like 'Gate Guards'.