Parsing for these would be appreciated:-
29 Across - "What TT competitors get back, or relinquish". DEMIT
26 Across - "Use four-letter word: the "corn" in Cornwall? SWEAR
12 Across - "this would be the making of one". TWELFTHS
(With the last-mentioned clue, I noticed that it was the only clue
without a capital letter at the start, so I don't know if this had any significance? Also, if the answer is "twelfths" why is the clue not referring to a plural solution?