As I recall, Glenn had a career change a little later in life so he was a first-year teacher when he became our Chemistry teacher. He was absolutely committed to what science was all about and every day was wearing the same lab coat he is shown wearing in the yearbook.
But Glenn was not a fashion fob, and when you look at the narrow ties being worn on Mad Men I recall the very wide ties that he wore daily. At some point during the year somebody got the bright idea that we should all wear wide ties to school, obviously to mock his own collection. I won't forget the funny look on his face when we walked in, but it was only a one-day event and then we moved on.
We should forget the ties. He was a pro, and loved what he was doing. I'm not sure any other teacher had any greater commitment.