This is the Ford Sierra (sold by Ford as the Mercury Merkur in the USA) (299-A Uncataloged) from Corgi. This was released almost 30 years ago in 1982. The Car is in MINT condition, and this seems to be an uncataloged color. None of the 4 Corgi guides we have list a silver body. So this appears to be an uncataloged variation.  The box however, shows its age and is pretty well used up. You should be buying this particular one for the Sierra, not the box. You simply will not find a better example for this price! (1:43 Scale)