I've now received the NTO. They are not offering me the discount and the charge has gone up to £70.00.
By law the Notice to Owner has to demand the full penalty, but as long as they receive a representation by midnight on 15 August we would expect the discount to be reoffered.
Here's a formal representation for you to send:
Dear East Hertfordshire District Council,
I understand that for alleged on-street contraventions, the enforcement authority is Hertfordshire County Council. I have seen no evidence to show that East Herts Council has delegated authority from Herts County Council to enforce on behalf of the county, and in the absence of any appropriate delegation of authority, it seems to me that East Herts Council has no greater ability to enforce this PCN than McDonalds or KFC.
Yours faithfully,
Of course the council will reject, but at that point you'll have the option to appeal to the Traffic Penalty Tribunal, which is actually independent.