I would dispute that a 60 year old Anglia is more polluting than a modern diesel. Add to that the older cars tend to do fewer miles as they tend to be toys rather than the main vehicle.
Old cars have paid their due regarding car tax and they are not using valuable recourses that a building a new car does.
Quote from The Telegraph:
According to Emma Bicknell, from insurance specialist Footman James, a recent survey by the company showed that more than 50 per cent of classic-car owners drive them less than 1,500 miles a year, with another 30 per cent covering up to 3,000 miles.
The survey also singled out owners' fears of proposed "green" policies as the biggest threat to the classic car industry.
Chris Cunnington, chairman of the Triumph TR Register, reckons that up to 70 per cent of members' cars never exceed 2,500 miles, while Chris Seaward at the MG Car Club puts the figure at 3,000 to 4,000 miles.
Club membership is popular within the classic motoring fraternity. The Federation of British Historic Vehicle Clubs has 500 member clubs, which hold regular social and vehicle events.
In a report published in 2006, the federation reckoned that 406,000 of 540,000 historic vehicles were roadworthy… but travelling fewer than 900 miles a year on average.