Here's a comparison of a no name Grand Canyon, a WGM Grand Canyon mold, and a regular WGM. The WGM Grand Canyon style insulator is in the center. Note the narrow wire groove and the less pointed, more rounded dome, which is similar to the regular Grand Canyon.

The dimensions are of the center insulator are: width: 2 15/16", height: little under 4".

The center insulator was recently purchased from John McDougald and he claims it is the Grand Canyon style listed in his price guide. But Mike Miller, author of the WGM article in the latest Crown Jewels, said it's just a mold variation of the postal style.

It does not have the "braille bumps" on the dome like a regular Grand Canyon beehive. The threads are different too.

So who's right?