Both of these insulators have an "X2" shop mark on the dome, but it's clear from the photo that they were not from the same mold. I shimmed the Brookfield to make the heights match, and the blotouts generally line up, but the extent of the "&" could never be covered by the blot circle as executed. I don't have enough variety of AT&T or Brookfield blotouts to make any kind of meaningful comparison.