Not only did we see the Chatsworth Freuds, but we were also shown their Leonardo drawings, shown recently in New York and about to return to cold storage. The greatest is Leda and the Swan (c.1505), a powerful study of female, animal and plant form for a lost painting:-

They also have a remarkable group of grotesque heads, one of Leonardo’s perennial obsessions and a symptom of his interest in the pseudo-science of physiognomy:-