What I'm studying is the yoke itself... Can you provide a 90° side profile photo Trevor, or confirm in text whether the yoke cants forward, as it appears it might do in your fourth photo?
Photo angles play tricks and I (personally) can't judge just with that pic; seems as if the near side trunnion leans forward and the far side might not, and the motor center aligns with the post, making all parts actually vertical?... but if I'm viewing wrong, then I have to think this fan began its life as a bracket fan...
Good observations Tony, a keen eye you've got........