Since 1st April The Traffic Management Act (of 2004) has given the local authority permission to use the postal service as a means of officially serving a PCN.
May I ask a bit of a daft Question here.... but were you parked illegally and possibly causing an obstruction ? The reasons you give for your appeal seem to be *excuses* as to why the fine should not be applied, not justifications for why you parked in that particular place. There is usually a very good reason why parking is not permitted in certain areas (access for emergency vehicles, limited space for overtaking, pedestrianisation etc etc).
I have to disagree with you David - if calculator was parked illegally, he broke the law, and I hope he has to pay his dues.
Although I do agree that local councils don;t give you any leeway in regards to parking in an area that has no designated parking, but you refuse to pay to park and simply post a letter, the law is very clear 0on what you can and can't ni regards to road markings.