Excuse what might seem to be major bragging here. It's not my intention, but maybe somebody can cite some information that could help me.
In doing genealogical research on my family, I learned that I am a descendant of Sir Thomas Stanley, 1st Baron Stanley. It didn't occur to me at first, but I later wondered if this was the same Stanley family from which John's mother, Julia Stanley, descended. Sir Thomas lived in Lancashire, close to present day Liverpool. There are several Beatles biographies that state that Julia did indeed descend from the same Thomas Stanley. If true, that would mean that I can call myself John's cousin. That's all well and good. Certainly, by pure accident of birth, it would be a cool claim to make. But I've never seen a complete genealogical study of John's family from Thomas down to Julia, and quite often, claims of relationships are made based on incorrect information.
If anyone here stumbles upon John's genealogy (Stanley, not Lennon), please let me know.