I've had the same thoughts. He looks slightly apart in those later publicity photos.
FP, I enjoyed reading about your awakening. I don't think I ever quite got to choosing my guy, although I know Glenn auditioned. I needed something to feed the obsession and there just wasn't much Eagles material around.
This is a photo thread and I've taken it onto a new page, so here's another from 1979/1980. He's even wearing a watch!