I can only advise caution. You assume too much when you say 'charges of my small claim fee, interest etc that the court will inevitably involve'. There is no guarantee that the court will find in your favour - if the court finds against you, YOU will end up paying those costs. Certainly, my understanding of DSR's incicates that bespoke may not be included, and waiting until 2 days before delivery implies that item was already built and possibly even despatched. You don't say why you cancelled the order - I would expect the court will look for a very good explpanation of your actions if they are to side with you.