Van Cleemput, Marcel R, The Great Book of Corgi 1956-1983, New Cavendish Books, London, 1989, pp 353 - 355
According to the author, only ten of these special models were made, primarily for VIP guests at the world premiere of the film. There is no sign of a plaque on this piece, so, given its provenance, it is possibly a pre-production prototype.
See Christie's, Fine Toys, Thursday 20 May 2004, Lot 305 for a similar model that realised a world record price for a Corgi Toy at 5522 pounds. The accessories drawer on this model is a slightly different shape.