'Delivery of' means that it sounds the same when spoken. So, in fact, you are looking for a 5-letter synonym for 'rhubarb'. 'Stinker' is the definition. Difficult to find a hint for that actor without giving it completely away. I'm also struggling in the top right corner. Help with 'musical stops' and 'fold nappy' would be good. There's an obvious synonym for nappy which would seem to fit, but I can't begin to parse it.
As for filling the grid, I don't really know what I'm doing, other than making things look neat and symmetrical. I think I've got the extra words in the down clues, and this has given me the third word in the phrase, but the across section is still resisting my efforts. It would be nice to know the word lengths in the phrase!