Quick crossword No 121

Thought I'd have a go at this one after your tip on Cryptic Sunday. A bit tougher than expected, but stretching in a good way. Particularly appreciated 7a, 12a, 22a, 23a, 3d, 13d & 21d among others. A couple too far out of the orbit of my GK, but that's no criticism. No quibbles of any significance, so just thanks from me. A couple of spoilery comments in reply.

Nice one. A little on the tricky side for a QC perhaps, but all fair. I see a reference to "Michael Rosen" in the unches top and bottom. What's the significance?