I do believe these are electrical fence insulators, aren't they, I found them in the field behind a friends house when I was about 6 years old, and I just recently salvaged them from a box containing things from my child-hood, I have some wall-tube insulators too, I just can't find them. Some weird styles here, like the square one in the back middle, or the two-piece ones, the one at the back right, and the two second from the left front row. The tiny one at the very far front right is marked PP inc.. The biggest one is marked with two S's in triangles.