Meursault
Thank you. I think I have got this cracked but I used Excel which I imagine the setters and editors do not think necessary.
I have got 23a as a p and 23d as an i, agreeing with 31a which is also an i, with two possible answers up to that point.
Incidentally, your posts contain lots of apostrophes, using a symbol which Norah said had been banned! She suggested that that was possibly the reason why my post was not accepted.