Seems harder than usual this week. Struggled through to last one: 23A: Stage king free of inner character (7) A-C-A-D. By the way - 3 Down is a (5,4) not a (4,5) as printed.
HARRY GRAHAM wrote books of "ruthless rhymes" in the age of Galsworthy, and Grigson edited a book of nonsense verse, so I think GRAHAM a good candidate for 21d.