I used the pepipoo forum for help
They wrote me an appeal letter which quoted cases where the issuing council were found in breach of their duty of care
Six weeks later I received a reply which dismissed my appeal on the grounds the pcn was issued within 14 days of the alleged contravention. This was the original pcn, not the one issued almost six months after the event. They made no reference to that which was my grounds for appeal
The pepipoo people then told me to go to an independent tribunal as I had a strong case. If I lost the fine would increase to £60
We filed for tribunal, which is all done online, and Manchester Council gave up and decided not to contest
So I won