This belief of Rutherford sounds like it was conceived from the fantasy novel Angels and Women published in 1924, which was based on an earlier novel entitled Seola in 1878. The WT had Seola refined to their liking and was then republished in 1924. Look at the difference between the two books with regard to the Great Center of which Rutherford was talking about, particularly the star Alcyone.
Angels and Women - 1924
Now notice in the original version of Seola we find out how many stars surround the Great Center. For some reason Rutherford wanted the seven stars not to be mentioned in the edited version. This definitely makes a connection to the Pleiades constellation.
Seola - 1878