This is a CD126, most likely in the [EIN] [150-180] range. There was probably another date on the insulator, but with the embossing on the crown of the insulator, the mold would wear out quickly and the embossing would become weak and unreadable. Brookfield has probably 300 different color and embossing combinations in this CD number alone. This is a very early style of insulator with the 45 Cliff St. on it. That was Brookfields earliest address.
Your insulator in mint conditionn would be in the $5-10 range in blue. If it was purple it would be in the $7500-10,000 range!! Keep looking and nice insulator.
I figured there was. It is either Brookfield CD126 [150] or CD126 [180] depending on how the embossing is aligned. Both are still in the $5-10 range.
The numbers I am using are from John and Carol McDougald's "INSULATORS: A History and Guide to North American Glass Pintype Insulators" "Copyright 2007"