Now, like those a lot quicker than me, I think I may finally have sorted out most of the mistakes in today's Herculis, (16D=13D, 17D=16D, 17D=missing).
I wonder if it Is possible that 14A and 18A are similarly affected?
Many solvers seem to have FLAN and WHINCHAT for these two clues, but I didn't get FLAN and frankly I am still not sure about it.
What I have is PLANCHET as an answer to the clue about a blank metal disk.
This, for me, is a much better answer to 14A, and fits perfectly in the lights for 18A, and so I wonder if this is yet another misnumbered clue.
What do more exerienced solvers think? Just co-incidence?
Belerophon, a planchet is as you say a disc of metal from which coins are struck, however flan is an older variation with the same meaning. Whinchat is the correct answer for 18a. The one missing clue is I believe,17d ambition.
Wiki has this - Prepared disk of metal on which the coin design will be stamped. Also called a 'planchet' or 'flan'. In practice, 'Blank' is also referred to the un-struck or flat side of a uniface coin or medal.
bennem3 has contacted the Telegraph and was advised to send in the Crossword with 17d left unfinished - he didn't mention any other mistakes. Apparently, 14a was an identical clue in the Express and the answer suggested was FLAN. Hope that helps!