This kind of crossarm construction was very popular within Boston Edison territory for decades...I'd say right through the 1950s. Some older poles like this one (many are weathered cedars) still are standing. Boston Edison always used glass insulators. This continued through the 1960s. Almost all were CD 164s, 165s, 165.1s and 167s for local distribution and some Kimball glass for higher primary voltages.

Note the telephone sign on the left side of the building.