I'm afraid that dressmaking is conspicuously absent from my CV, but the OED confirms that a FENT can be a remnant of cloth or (in some places) the binding of any part of a dress. It also confirms that a FENT is a crack or fissure.
I've no doubt that FENT is the right answer as with due respect to the other '?ENTONs', James Fenton is the most famous by a mile - he won the Queen's Medal for Poetry in 2007. I agree about the potential ambiguity, though - the clue would have been much better written as 'Contemporary poet James not on crack'.