I have that LP but other than admiring the fine ancient tree at the back I've never really wondered what was going on in the picture. Hooded effigy hanging from an ancient tree - in English folklore, traditionally associated with rural hangings of highwaymen or bandits. That's my interpretation anyway..
I have that one..........somewhere....
I saw Horizon on a couple of occasions around the time that that album and 'Post Motown Bop' were released. They played 'The Inventor' and I remember him saying something about his father.
I think you are right John. They would have come out over here on UK Liberty or Sunset I think and I don't recall ever having seen any of these from the 1960s. Buddy Rich Libertys, of course, were/are ten a penny.