You know, it may be a McGraw Unistyle from after McGraw Edision took over Line Materials.....what made me think that is due to the slipfitter design......and the design closely resembles the concept used in McGraw Edision Unidors. So this one if it's from 1967 I believe or after then it's a McGraw Edision....for sure this fixture is from 1966 and after due to the location of the Photocell bump.....mine is farther back right above the slipfitter and is from 1965