Mummies, shrunken heads, body parts, etc, no not pleasant but part of history - life and death.
So, displays in museums should only show the 'nice, pretty' bits of the ascendancy of humans that we approve of? Homo sapiens are not a pleasant species, we unmercifully kill other animals and ourselves, by nuclear bombs, genocide, etc. Ancient civilisations tried to preserve their dead by means we now look down on from a great height and cringe at - but it was their culture, their history. Isn't this what museums are supposed to be about, looking back through the ages at all aspects of civilization - the gory and the splendid, it's all part of what we have become now.
So, hide the shrunken heads, mummies? sweep them under the carpet and pretend they never happened?