There are contemporary first person reports from the people who collected/stole the artefacts in museums. Michael Leiris collected items - some of them ritual items made from coagulated blood - that are still on display in the Musée Quay Branly in Paris. His description from 1931 seems honest, hair-raising and hardly morally ambiguous…
https://www.modernghana.com/amp/news/800468/who-is-afraid-of...