1972 Upper Control arm question..

The inner sleeve fits on the rear bushing on cars with 10" brakes only.
Ok.. But its "Not" part of the control arm, correct?

Had a good go with the tools to remove the old bushings. Once they broke free from the bore, I noticed the "Extra" sleeve on each arm. Thing is there was corrosion on both ends wich indicates to me that it was not part of the arm. Or it broke free many years ago... Just trying to understand this odd setup. Car has KH 4 piston discs.

Woodie