Hi Erik, The 360 Turret ring is sold in two variants that I know of,
A metal ring with Three bearings to ease the Load on the Turret and I have not seen one with the Cut out for the "Slip ring",
And the ABS 360 Turret Ring (No Bearings) which does have the Cut out for the Slip ring,
So maybe Mr "Luvtoflywarbird" was using a 360 Metal Ring without the cut out for the Slip Ring.
Just a thought,
. Shaun..