OP, the £160 offer is IMO a rip-off, particularly when you consider that TEC officers' decisions are subjective. With TEC the key issues are not of law IMO but whether a respondent's (that's you) submission presents sufficient relevant believable facts in support of their grounds.
To this end you absolutely MUST expand on:
I don't have an evidential basis for this, as I just didn't receive some of the correspondence that would have allowed me to submit in time
What docs did you receive, a simple timeline would suffice:
PCN - if served to vehicle ****
NTO/Enforcement Notice ****
Representations made, yes/no on *****
Notice of Rejection received/not received dated *****
Charge Certificate received yes/no, issue date *****
Order for Recovery received yes/no, dated *****.
The NoE will include a latest date for payment. I suggest you pay at the NoE rate.
Why? Isn't this giving up?
No, it's not. Paying the NoE simply caps your liability and avoids the staggering enforcement fee being added. It has NO effect on the likelihood of success with an Out of Time submission, none at all.
If your OOT succeeds then the compliance stage fee(£75) and surcharged penalty are refunded and you're back to whatever stage applies in respect of your grounds e.g. didn't receive the NTO, made reps but didn't receive a reply etc.