Remember, these are all mirror images from bumping against an embossed insulator. I measured the size of the letters on the 133.1 and the 120 and 135, and I think they match in size and font. The "K" is especially telling. A weird leg matches the K's on both the 135 and the 133.1. Not absolute, but pretty well implicating these insulators as being made in the same factory. (I'd love a picture of the 135 with "HOMER'S MOLD" embossed on the dome!)