This may help, but if you are not a full member (yet), you may not have access to it, sorry, that's how it works.
https://www.two-sixties.co.uk/mgoc26...al-Part-number
If you haven't yet applied to be a full member, you can do that by sending a PM here to "Tim" with your email address, and ask for a full-membership request questionnaire to be sent to you. It really is worth while (essential?) once you own a 260, Rover or MG. Believe me; it has already saved me hundreds of pounds, not to mention all the valuable advice!.
David