I just replaced the Upper Control Arms on my 82 300D turbo last week.

I went ahead and replaced the whole arm. The whole arms I purchased came with the top bushings pressed in already. I also replaced the torsion arm bushings.

As adviced by forum members, if the arm is old, it may be prudent to replace the whole arm as oppose to just the bushings.

FYI - the torque specs 80 Nm - arm (19mm bolt and nut) to body of car
65 Nm - torsion arm (17mm) bolt
45 Nm - arm (17mm nut)to (don't know the name ---ball joint of arm bolts on to metal bar that is on wheel )