No eBay APP ID and/or Cert ID defined in Kunena configurationWill do mate. Found the one on UK Ebay that Scotch recommended 15 quid delivered. An alternative is available on the German website & although I don't want to knock them as they provide a lot of discontinued parts for our bikes I found the 30 quid plus shipping a bit expensive for a radiator cap that's not even OEM.
Btw I replaced the cap last 20 years ago, when the OEM one was still available, I only noticed the outer rubber seal had started to perish when I went to complete the cooling system service today.