Corrected question: Which one of you knuckleheads is Person 2?
From Paragraph 55: Matthew Steinmann wrote to Person 2: "I will talk to KB about that...."
Person 2 was plainly not in on the fact that MS was a KB alias, so it's not likely to have been old co-conspirator friend Barbara Asbell. Person 2 was used by KB and has been turned into a cooperating witness and unindicted co-conspirator.