Many thanks, tyke, and for others' kind remarks. I must confess, when you asked for a parse, I thought it signalled the kiss of death for my dodgy effort. Perhaps SS's überanagrams might also be called rhubarb crumbles?
Peterm ... it was the 'black piece' for coal I couldn't fathom - I was thinking 'lac' or similar!
Well done anyway - IMHO the standard of clues makes it harder to win than ever!