Does the magnetic cylinder need to fit the cam then be pressed down, then refit and press down again? I cannot get it down far enough for the rotor and cap to fit.

I had the same problem when I installed mine. I ended up filing off a little of the bottom of the rotor and using a deep socket, tapped "LIGHTLY" on the magnet.

Had the exact same problem so I just pulled the dizzy and took the whole mess to the VW shop where I bought the Pertronix. Counter kid said to grind off the bottom of the rotor which I didn't like, so he took it back into the shop and came back with it installed. After I ask he admitted that he used a socket abd hammer to drive it on. After installing the dizzy the car never started again. Frustration set in so the car went on the trailer to local Porsche shop. The Pertronix bench tested fine but the car would not run with it installed, ran fine with points and condenser. So be careful about hammering things on. The VW shop replaced the Pertronix with another which I did not let them install and it runs great now.

Thanks for the feedback. I will hopefully have time to tap this in place tonight.

Pertronix and new coil installed and car runs! Tap tap tap, vrrooom.