Thank you to all of you who responded to my request for hints. In the end I didn't need them as I solved all the answers before coming back to my laptop. Once I'd got 15ac, others fell into place. Isn't it always the way.
But I have had problems with parsing a number and with some unusual words. the parsing has escaped me with 1d, 3d, 18/26, and 30ac. I'd not heard of 10ac before or 23d. The Amercan dramatist was a mystery to me but I've now looked him up - a Pulitzer prize winner no less.
FOI was 27ac, LOI was 23d and CODs 8d, 13d (which made me laugh - it took me ages to spot the definition) and 26d.