These are both No Embossing Canada [080] "whittle" molds.

These two insulators are both from the same mold, however the one on the left is an earlier "smooth whittle" while the one on the right has a heavily whittled surface.

Notice the narrow tapering threads on the insulator on the left compared to the extra wide sharply threaded pin hole on the right. A "standard" 1-inch pin will only screw half way into the insulator on the left, while the insulator on the right will only catch the threads on the last "half-turn" at the very top of the pin hole.

The narrow tapering pin hole can often be seen on the "slug plate" CD 143s too.