How were complex, compound-curve geometries manufactured in the 60's without modern cad/cam/robotics tools?

I stumbled across an image of the classic Ferrari 330 P4 from 1967. The thing is stunning, but it got me wondering how they were able to consistently form those curves (and get perfect mirror images for the left/right sides), including the domed canopy.

I recall lots of things from the 60’s being mass-produced with compound-curve geometries (furniture, vehicles, aerospace and appliances for example) and I was wondering what the general techniques to making that stuff were back then? If they were using molds somehow—how did they get the molds to be consistent with each other?

Also, how would you draft the blueprints in 2d for such things without 3d files?