If you were to make a list of the greatest British cars, the original Jaguar XJ6/12 would almost certainly feature on most peoples lists.

Granted, the car doesn’t innovate or bring anything new to the luxury car market, but it is the sum of its package, styling and Jaguars rich heritage that marks it out as a trendsetter.

Originally offered with the 2.8-litre and 4.2-litre straight-six engines, the graceful four-door became the default 4 door saloon design template for over two decades for the brand.

Today, these original Series 1 cars have become the most desirable – and easily the most valuable – as the purity of the concept singles it out as a design classic.

The Daimler Sovereign is essentially the same car as the Jaguar XJ6, and share everything with trim and badging differences.

The first Daimler Sovereign arrived a year after the Jaguar, but curiously have traditionally been cheaper to buy used than the Jaguar.

Offered with the same engines, the smaller 2.8-litre models ar...