Re: Not only their problem - ?
The UK government makes the basics for any registration number freely available. https://www.gov.uk/check-vehicle-tax gives you vehicle's make and colour, year of manufacture, month of first registration, fuel type, cylinder capacity and more. https://www.check-mot.service.gov.uk gives model, plus date, mileage and pass/fail for each test. There's enough there to allow a rough valuation.