I know that Part I was published while John McCarthy was working at MIT in 1960, in which he describes the LISP language, which he had invented 2 years prior, and is today considered one of the most seminal papers withing Computer Science. However, I can't seem to find any information about part II, other than an unreferenced sentence on Wikipedia stating that it "was never published".
If somebody has any information concerning the paper, I'd be very interested to hear it. For example, was it even started? What were its contents supposed to be (about)? Are there any drafts in existence? Why was it never published?