if its pre booked you can get away with no tax, no mot
insurance is min 6 points but stays on just like any other offence
the fixed penalty i aint got a clue what thats for as you must have admitted to something to recive it
so theres part of your story missing my friend cause as much as i think the old bill are dicks they dont make mistakes that fucking stupid\
oh and the old bill dont issue a dvla fine, they report you and dvla issue the fine 3 months later ( i discovered

)
you will get away with them but the insurance your fucked mate