Am trying to solve this problem with a help of imagination.
I believe we will have a very advanced biology science soon. A lot of people who lost theirs legs,or arms,or eyes, or had any other damaged parts (as a heart,for ex)get a chance to use substitues. So humans become cyborgs more and more.
So the question is if cyborg is still a human or homunculus? What if this person will be 30% natural only after a car accident? Is he still a human? Should this person have the human rights? I want to say "yes".
Then if we theoretically create a total cyborg but with a copy of personal mind identity of a real human. 100% copy. Is this cyborg a human? Should this one have the human rights? What if he feel, suffer and can be creative as a human his mind was copyied for? I want to say "yes".
But what is more important is the fact human rights are not protected yet for many humans even. So unfortunately, our society is not totally ready for such things as cyborg rights...