jime

Hi, I'm new to this forum, and I have joined as I have recently got a 1981 XS500. I have already managed to source numerous parts from ebay, however I'm having problems finding a new oil filter cartridge, either the original large size one, or the later update which I believe was an adapter seal, allowing a smaller cartridge to be fitted. Does anyone know where I maybe able to source this in the UK? Thanks Jime