The source of the problem.... a knotched bellhousing.
A 1/32" washer is about 0.8 mm. Perfect for gaping the speed sensor.
The reference sensor sleeve is aluminum, with an ID of 15mm, and OD of 18mm.
Modified bracket, is the same as the old one, but it has been bored out to the OD of the sleeve. Naturally, the sleeve has a shoulder (to prevent it from falling and contacting the flywheel), so the bracket was also bored accordingly. While you could made your own shielding and modify the original bracket, unless you have a lathe, it's better to buy the parts for $100.
Since the part where the wires go in the sensor was crumbling, and could lead to wire breakage, and loss of contact, I filled the gap with RTV.
So it looks like Porsche eventually realized that notching the bellhousing was a bad idea, and stopped doing it on later cars. Nice Bulletin Chicks!
The spacer (#32) that I referenced earlier, was not needed.