XJR6 crank damper repair

[j.l.hodgkinson77971]

Hi Everyone,
The crank damper on my '95 XJR has started to fail, with the outer pulley which drives the alternator and water pump slipping relative to the central hub and other pulleys, I assume due to the rubber bonding them failing. Does anyone know where I could get mine repaired or exchanged (north west UK)? If I end up buying a replacement from a breakers, is the one for the supercharged version any different? ie the four bolt holes in the hub to mount the extra pulley?
Any advice appreciated,
John