The sleeve you have on the inside of the arm looks like it functions about the same as the bearing retainer collar on the rear axles. If the bushing has been sloppy on the original hole on the upper control arm, they have pressed a retainer sleeve over the bushing so that the bushing itself wont fall off. In your pic, it looks like you have removed the internals of the original bushing and the outer shell of the bushing is still in place, like the collar is holding it there?
I removed all four bushings last weekend from mine and I had some major problems with the last one. First three came out without any problems but on the last one the "face plate" on the inside side of the bushing went inside the outer shell and kinda ballooned and stretched the end so that there was no way it could have been pressed out completely, I got it about 2/3 way out before it stopped. I had to cut the other end off the bushing off and press it out to the other direction.
