Never tried anything like that, you say these add ons are body parts? with bones? I'm a little confused, particularly why you didnt merge it all together. Or these add ons were added to the .cr2 after the fact? How about as conformers? If it's working then good enough I suppose... It would be a little problematic if the figure went through QA ok and then some obscure bug showed up. I can think of a few forum members that might know about stuff like this, though I haven't seen any of them around here lately. Have you tried asking this question over at Rdna?