UrS6 rear upper control arm - a few questions?

[Radek]

Hello Audifans;

Would anyone know if part number 443-505-153B (outer end of the control arm that attaches to the wheel hub) is available separately?  Searches online only come up with the whole arm (443-505-351/2P).  Even better, is it possible to change just the rubber bushing, since the rest is still good?  It seems that the bushing is the wear part, I have two more sets from a V8Q and in both cases just the bushing is gone.
Also, is there really a right and left control arm (that's what FA says) - they look pretty much the same!
Thanks!

Radek
91 V8Q 5-sp
88 90Q
96 UrS6