Buckrogers

Hi I am trying to locate some new engine pistons for a friend. Does anyone know of a company that makes or supplies them by chance? Jaguar XJS Coupe , 1983 V12 (High Efficiency) 5.3 I have tried a few places so far with no joy: Jaguar Heritage Parts - no but very helpful martinrobey.co.uk - no rob-beere-racing.co.uk - no xrnengineering.co.uk - no The specific part is no longer supplied by Jaguar. Thanks in advance for any help. Buck