Having come back to this after rather a long day, I still have four clues to do, in spite of having already received a hint for one of them. Would very much appreciate some further help.
23 It was necessary once etc. (I know the definition, but can't work out the correct word)
24 Note nothing new with square cloths etc. (again, I thought I had the answer, but it was not in the plural, so no good I presume.)
47 Fifty per cent of Oaps having ding-dong after rowing.
and finally
39 Pillbox closures etc. ( I have gratefully received a hint but still can't get it.)
Very grateful for any nudges if anyone is passing by.
Thank you.