Defender 200tdi injection pump nylon washer

Hi all,

Anyone know where i can get hold a replacement nylon washer from a 200tdi injection pump (the washer that sits under the diaphragm and spring) - cant seem to find one anywhere. Or if you know the thickness of one so I can buy a generic replacement. Lost mine when fiddling about with the boost pin - its now smoking so guess i need to replace it.

Thanks,
Chris.