Looks like this thread has gotten "off-topic' from the title . . . . Re OP . . . . Perhaps I missed as similar post (haven't read all the posts), but, IMO, the moon's center of mass is offset slightly toward the earth due to mutual gravitational attraction (during lunar igneous-phase formation) - much like 'tides' - a denser lunar interior (asthenosphere?) toward it's nearest neighbor - earth. A similar (but much less so) effect may contribute to the earth's 'wobble' (precession).