I received an e-mail from an ICON member who asked me to post a picture of the embossing of a Boston Bottle Works insulator. The Kevin Lawless list refers to "embossing on the base of the inner rim".

The following post shows the "Boston Bottle Works - Patent Applied For -" embossing around the inner skirt rim of the CD 158.9. When you hold it in your hand, the embossing is easily read, but it a little hard to see in the attached photo. I will also post a picture of the embossing of a CD 158 which can be more easily seen in the photo [id=631100331]. The Boston CD series all have similar unique embossing on the inner rim of the insulator.