Thanks for the advice, Rusty. The puzzle is radial with 48 clues, all with 6 letter answers.
19 is: Teak-like tree to plant NW to SE in units; and letters are t??las. The positioning of the answer is in the NW/SE part of the grid, which may be relevant.
33 is: Reinforcements involving new Scotch tape; and letters are t??rts but in this clue the wordplay leads to the answer with an extra letter not entered in the grid; in this case the letter is, I think, S.