Got all the clever stuff - I agree it's a considerable feat of grid construction - but annoyingly I can't decide which of two (to me) equally good answers to 27D to use. The ambiguity is in the initial letter. The earlier (alphabetical) possibility isn't in BRB in this singular form, so I suppose it starts with T, but either way I can't parse the clue to my satisfaction. If it does indeed start with T what is "grass" doing? If with the other letter shouldn't there be an indication that the answer isn't in BRB but is somewhere else (if indeed it is). Annoying to be held up in such a silly place having got what appears to be the difficult stuff. Guidance welcome!