A further advancement on organ donation or mechanic galvanic parts - the surgical implantation of animate organs.
Necrotech skin regenerates over wounds at a much faster rate than natural healing. All it requires is the consumption of raw meat. Necrotech eyes give prey sense if the continual nightmares can be overcome. Necrotech limbs can replace limbs - or even be added to someone's body where no limb was before. They will work even if not in the correct place, obeying their owners for the most part. Necrotech internal organs replace lost or diseased organs. They will never shrivel or die and occasionally do not cause too much corruption in their host.
All these body modifications require specialise skills of a Doctor and Alchemist - the only trade off is an increase in meat needed to be consumed, and the regular injections of anti-rejection drugs and Angel. Miss a shot of Angel, and you have the Plague.