Pabst glasses

My grandfather worked for Pabst in Milwaukee and died when I was about four years old. I only have vague memories of him. (34 years ago).

However, I recently inherited some Pabst glasses from my mother. I have twelve of the glasses on the left, which I know are quite common. However, there is only one of the glass on the right.

The twelve say "Pabst Blue Ribbon Beer" but the other merely says "Pabst Blue Ribbon." No idea why...but maybe interesting to people.

I have no interest in value/selling, etc. I keep them for the sentimental value. Nonetheless, If somebody knows about them though, I'd be interested in learning.