I see Incandescent has beaten me to this, I've therefore edited my draft.
You upload externally and post links here.
Any Notice of Enforcement would include a creditor council and a reference number. The latter would normally be the PCN number. As you know the veh reg number, I suggest you get online to the council's PCN website and check your details. Alternatively, post the ref. number, council and your VRM here.
IMO, paying at this stage is recommended because it caps financial liability without hindering in any way your ability to engage with the 'Out of Time' procedure. If the notice is a Notice of Enforcement when was the 'pay no later than' date?
At present I don't want to get engaged with why you haven't received any of the reams of correspondence which would have been sent to the registered keeper because it's secondary to getting facts on show. Not receiving notices from a council is not unique.