I have another question. I have these two CD 133 H.G. Co. insulators. They are the same embossing index but they have two different styles of embossings. Why is this? Also, why does one use a regular 2 in the date but the other has a looped 2?? I have seen these two different style twos in other insulators also, like H.G. Co. 151's. Does the style of 2 mean anything? Any help in answering these questions would be greatly appreciated. Thanks.