help with international sterling hallmark


I am trying to figure out as much as possible about this hallmark. It is on the underside of a chalice. I understand that it is made by the International Silver Company of Meriden, CT.

However, I am wondering what the E970 might mean. You will also see that there is an “11 A” stamped off to the side as well. I cropped out the “11 A” from the photo so that I could get the image under the size requirements for this forum.

Apart from those questions, I wonder if there is any way to judge the approximate date of origin of this item from the type of hallmark used.

Thanks for your help.