Two of Graham's Seven Primitive Operators are car and cdr. These names come from the IBM 704 implementation; they could not have existed in the theory which came before it. Since those names were used, this casts a suspicion that the theory didn't have these functions, and therefore wasn't about Lisp.
What Graham's Paper is describing is a back formation abstracted from what they got running on that IBM 704.
I doubt that the theory had quote, either, which is the gateway to "code is data". Since code-is-data is the core of Lisp, a theory without code-is-data (like the vapid nonsense that is Lambda Calculus) isn't about Lisp.