Assuming we use transplant as give someone else, probably the eye.
In Naruto, giving an eye's insanely easy. Shove one eye out, in with the other, yowzers, they can see with the Rinnegan, just give them a couple days with bandages wrapped around their head.
I don't think there's any inclination that it would be the same for Hashirama cells of skin, and I do not know how skin or cells works more than I do eyes.