Don't know about you but I've never seen a grooved based insulator. Here's you chance to own one. This some what crude looking and has snotty milk swirls. It is embossed MONTREAL TELEGRAPH on front skirt and Co on rear making it an EIN005. This piece has many larger sized bubbles so no matter how you display it you will see some of them. Ofcourse you will always see the glassy dome no matter what bubble or cluster of bubbles are your favorite. The last thing to note before getting into the condition is that a good amount of glass squeezed between the molds on the inside edge of the base. In doing so the actual base that is supposed to be thicks up at least 1/8" around the insulator. Now as for condition, it took a ping right at the base as can be seen towards the right side in my pic.
Book doesn't give value of charector insulators. You can have this one shipped to your door in 2-3 business days once a payment of $75 is made. I accept Pay pal in a non fee mode as well as personal and money order checks. First email saying I want gets. I will combine shipping to save buyers cash so see what other insulators I now have available at Icon. But email me if you want this one for sure before looking around for others. Otherwise it may get away because of my first email policy.