OP, the NTK is indistinct. Pl repost so that everything is clear.
The alleged breach occurred in Sept, therefore the 'old' CoP (for this operator) would apply.
By whether the signs comply with this CoP or not is immaterial* because your husband is past the time when he could challenge this with the creditor and therefore access the IAS which means that the next step for the creditor is court. And as I understand it, courts only consider the law and compliance or otherwise with a CoP carries little, if any, weight in their deliberations.
The next judicial step is court.
*- sometimes factors have a foot in both camps i.e. within a CoP and a condition of forming a contract.
As your husband was not the driver, then this matter is simply one of whether the creditor may hold the keeper liable for breach of a deemed contract entered into by the driver with the creditor.
Only the Protection of Freedoms Act allows such a transfer of liability and therefore it is compliance with this which counts. OP, here it is:
https://www.legislation.gov.uk/ukpga/2012/9/schedule/4/enactedMuch rests on the wording of the NTK, hence why we need to see a clear version (redact those parts as previously advised).
