I am 98% finished with _Crow Killer: The Saga of Liver-Eating Johnson_, and it treats the tendency of Johnson to eat the livers of the Crow warriors sent to kill him as fact and corroborates this feature of his vengeance against the Crows with testimony from "White Eye Anderson," interviewed for this book long ago, and who was an acquaintance of Johnson in his later years, and from testimony and letters of Del Gue, who, it seems, only died in the early 1900s. I'm very interested in finding Johnson's own words, especially since the book makes it clear that Johnson was a dour type, and chose his words carefully and only to those whom he liked.