They did exist,  but were a local gang more than a  Everton only gang , based around  the walton  rd ,county road area  there were lots of different  gangs a out at the time in the area of which they were one.
Think half the time the same people  were under a different  banner every few weeks,walton mafia,  Levo, Dely mob, ect.  Till a new name popped up  and allegiances  and allies  changed.
I was only a kit  at the time but  there was graffiti  a d one or two names of older infamous  lads who people said were in it
She was right about the Millwall  incident  as  one of the reported  members  was seen stabbing  at least two  in the st end at the time, anybody  that was there will recall  the fella  on the boys pen cage  getting stabbed  repeatedly,  that was one of them.
As was a Rangers fan hit with a hatchet  down one of the side streets by Goodison  after the tommy Wright  testimonial,  luckily for him it hit his shoulder.
The  walton road ,county  road area ways had  big numbers  at the Everton game .