I'm guessing that 'prototype' uses a ring because the pickup is so shallow. The ring keeps it from wobbling, especially if the bottom edge clears the pickguard. I usually mount the ring after the pickup is in place and close to the correct height.
For Lollar Thunderbird and Senn Model 1 pickups, I use the identical process detailed in the following link, but with EZ-LOK 329-004 inserts:
Guitar and Bass Neck Threaded InsertsThe main difference is that I drill the hole about 3/8" deep and use a screw and washer when installing to ensure that the insert sits just at the body's surface. Then I use surgical tubing instead of a spring with a washer at both ends. This enables the pickup's back plate and the insert itself to take all of the pressure and there are no forces at work to pull the insert out of the body.
If you're tapping a softer wood for the insert, just flood the hole with thin CA and hit it with accelerator prior to tapping and you'll be good to go. It's an extremely solid mounting system that provides a very wide range of height adjustment, especially for Thunderbird pickups. These shots should help to give a better visual: