This film wasn't in the Anchor Bay Amicus box set, it was in the Anchor Bay "Tigon Collection". As with the Amicus box (as well as the Pete Walker and Norman J Warren box sets) the box was in the shape of a coffin.
Not a bootleg DD, it was available from The Dark Side website at one time (along with another release, Devil's Nightmare & Cold Eyes of Fear), although I can't remember if this was ever issued with a magazine.