^^^ Sounds like you're on the right track, oldu. Does the Baird's entry say anything about Alpha Beta Chi's colors or symbols, or anything else of that kind, or is it just a pure listing?
Greekchatters come and go, but there used to be a very knowledgeable person on these boards named "localsororities" and they were the go-to person for questions like this.
However, this is going back to the early 2000's when they were on this board. I think they even had a website that they maintained..I think it was an angelfire or geocities website (yes, that old).
I had contacted St. John's archivist with my request and my grandmother's maiden name and she said she found some yearbook photos and information! She is going to mail it to me soon! I will scan and post what she gives me so we can all see it.
I am now trying to figure out a fraternity called Sigma Tau Beta. I have a pin from that GLO with a Beta guard so I suppose it was a Beta chapter. The style of the engraving dates the pin to about the 1940s. I was told that there was a GLO founded in 1927 at North Carolina State College with that name. When I went to do some research, I found that the founding chapter was established at X.C. State College...I have never in my life heard of this college!
I love these historical challenges! The only Sigma Tau Beta I found was a local fraternity founded at North Carolina State on January 4, 1925 and survived until sometime in 1933. Its yearbook entry always lists it as a local group and never indicates that there were other chapters elsewhere.
The pen you have could be unrelated to this group, or possibly a high school organization? Kee tracking.