Not sure the Pirellis are numbered? Is it definitely a UK car? I've seen more Japanese imports for sale than UK cars, they often come without service history.
Good point on the numbering - I don't know about Pirelli's, I was just triggered by ED30 and assumed it would be numbered, if it had a plaque it would increase the chance of someone knowing it...
@OP does your Golf have any other distinguishing features...moles or birthmarks? modifications?
If it has come from Japan, your car will likely to have been purchased through an auction house.
They have a policy of everything gets taken out of the car, this includes radio, service book, spare keys and this all is meant to be sent on separately - probably to avoid theft in transit - but as they are dealing with multiple thousands of car sales each day, the stuff often gets lost / separated from the car - this seems a very chaotic process for such an organised country!
If yours does turn out to be an import, the good news is the Japanese usually are very meticulous over taking care of their cars, especially non-domestic ones.
