Here is a CD 102 insulator that I picked up at an antique store last weekend. It has no embossings at all. There isn't even a number on it. It's not listed in the price guide so I'm hoping someone out there can offer some info. This store also had a white porcelain version of a CD 143 with the embossing on the dome reading GTP. I was wondering if a porcelain expert could tell me if it's worth the 15 dollars that the store wanted for it.