The black rings are 'shaft collars'. Order on-line. I drilled and tapped holes for the eye-bolts. Drill bit, tap, and eye-bolts at your local hardware store.
17,Dec,19 21:50
This piece is only the size of a B-B
17,Dec,19 21:48
I pierced my fren close to the glans so I eventually had a small, thin 'bridge'. I cut it loose from the glans to clear the PA hole, but then since the remaining bridge was unsightly sticking up from my fren, I trimmed it off.