This evening I received an e-mail telling me that they're going to cancel it.
To get to this point took two letters, two phone calls, and eleven e-mails. Amongst other things I sent them a diagram of the street and three 740k pictures of the bike bay as attachments (I was tempted to make it five or six but I didn't want to take the piss too obviously). I sent one of the letters recorded delivery, and enclosed copies of the photos etc. I repeatedly asked them to send me more details of the alleged offence and to expedite the paperwork for a "formal representation", which is their "court" for appeals and I suspect a total farce. All of which, I hope, gave them the (accurate) impression that I am an unreasonable bastard who is VERY paranoid about his rights, and that enforcing this would be a LOT more trouble than it's worth.
I'm not saying that this is the best way for everyone to proceed if they get a ticket; it's probably cost me four or five quid in postage, phone calls, etc., not to mention time wasted. But if you don't think they have a good case I'd sure as hell recommend fighting to the end, and telling them loudly and often that you intend to do so - I don't think that you end up paying more than the full fine if the appeal fails, at least in the UK, and if the beaurocrats are taking as much flak as Westminster do for their parking
gestapo they may feel that they're better off caving in.
To celebrate I got about 1500 more words of the time travel thing written tonight, and thought of some ideas which will be taking it in directions I hadn't considered before. A VERY good evening.