I'm really sorry to hear about your dad Dave. I lost my mum in March last year, and although it never goes away, I does get easier to deal with day to day, I promise. It just takes time.
Now, speeding ticket.
be VERY CAREFULL how you proceed with this. If it was your dads car and the photo was taken after his death then his insurance is no longer valid.
Anyone driving the car on their own insurance under the 'insured to drive any vehicle bit' may well have been driving without insurance at all, as most policies require the vehicle to be insured by another person for the any vehicle bit to apply.
It is up to the vehicle owner to prove they were not driving the vehicle at the time or the Police to I.D. the driver from the photo., since circumstances mean neither of these is possible then I really don't know how they mean to proceed.
If no one pays it would have to go to court and who do they intend to summons?
I can see the headlines now!.
WANTED: 1995 18" GT Zaskar Fame in ink blue | USE Stealth forks or spare parts