Let me ask the question this way: What evidence do you have that the standard solution to the one-shot PD can be improved upon without creating losses elsewhere? My impression is that you are being driven by wishful thinking and misguided intuition.

For what it's worth, I have written programs that cooperate on the prisoner's dilemma if and only if their opponent will cooperate, without caring about the opponent's rituals of cognition, only about his behaviour.

Unfortunately, this margin is too small to contain them, I mean, they're not ready for prime time. I'll probably write up a post on that in the near future.