Mere - Etymology, Origin & Meaning [specifically mere (n.2)] would be a better page to link, as the Marley page says Marley is derived from the Old English mære, not directly merestone, and also mere (n.2) mentions merestone anyway.
Sorry if this is not the best place for this question, I am new here and I read the Guidelines but found it lacking on how one is best to contribute to the site itself, and not just the forums.
Thanks for the tip, it has been fixed. We’d prefer such communications by e-mail. The editor’s e-mail is linked at the foot of every entry page. Corrections are much wanted and greatly appreciated. The editorial forum is for erudite public discussion.