I think the hut and its contents would be worth preserving if they shed some light on the inspiration for, or process of writing, Dahl's stories. Whether it does that I can't say - except that I find it hard to imagine how his hip bone could be relevant. I'm also not sure that RD's bullying, infidelity and anti-semiticness are relevant to his writing, any more than James Brown's murder of his wife should be allowed to impinge on anyone's enjoyment of his music. Let writers' memorials be their books, musicians' be their music, architects' their buildings, etc.