Silverstone Auctions has consigned a rare, limited edition 1993 Porsche 911 Turbo S Leichtbau to its May Sale, taking place on 13th May at Silverstone circuit. The highly collectible car is, according to its Porsche Certificate of Authenticity, chassis number 51 of a very special, limited edition, light-weight and road legal version of the 964 Turbo, of which only 86 examples were ever made. Announced in…