I am coming from a background in SDRC I-Deas and with that software if you had two instances of part X and you decided you needed to make one of the 2 X parts a different part, you use a command called "Make Unique". You would then give the part a new name, say Y, and then instead of having 2 X parts you would have a part X and an identical part Y. You could then open part Y and make the chages you needed to. Doing a Save as Copy isn't really what I want because I would then have to remove one instance of part X and then bring in part Y and redo the constraints, that is exactly what I am trying to avoid.
Chris W