I'm sure it's staring me in the face, but I just can't see it. 24a. Essential piece of information he passed on to press. I have m?b so the only possibilities I can see are mob and mab. There was a Queen Mab, but I don't see the rationale for either. Help please!
I'm puzzled by this too and have cross-posted the same query.
Mob would do for "to press" as in "to collectively gather tightly around someone", but I can't see how the rest of the clue works either!
M is the centre letter (essential piece) of the word "information", followed by "he passed on", represented as OB (either "Old Boy" or the Latin "Obiit" for "he has died").