In response to Southpaw82 asking what I think can be done. The short answer is, I don't know. That's why I have asked the forum. This forum has been extremely helpful in assisting with getting a couple of parking charges cancelled in the past as it's brought to my attention various requirements that I wasn't aware of. Such as time limits, signage, etc.
I understand that speeding is very different from parking charges. I just wasn't aware of if there is anything particular we should be aware of in terms of requirements for mobile speed camera vans, or any specific requirements when a road has recently changed speed limit from 30mph to 20mph.
I wanted to check with this forum if there was anything obvious we should consider if we were to mount a defence. Forgive me if I am mistaken, but is that not the purpose of this forum? To share knowledge and experience on this topic?