Fair point. It is more about the psychology of the issue rather than the source material itself. The skull is as is. It was not reworked and processed and it stands as a natural and dark remainder of a common fate. The othet is a purposefully crafted ornament in a not natural context, which says more about the mind of the original crafter than a fact of nature.
That said, why remove it now. If amything that was even more of a curiosity, albeit a morbid one. I would have kept it. I am aware of legends and stories of such cruel local lords of the middle ages that they had a fabled chest decorated with human skin. Just a legend. But that speak of the reputation of a long gone family, doesn’t it?
Edit:
Now, with the binding removed, the text itself will be fully available to view, both at the library and online.
Even without that binding, the text itself still preserves some of its nature. It does make you feel uncomfortble, to know that the original author had done that on purpose.