Hi Tim Hooper,
I remember being told of Turnbull being disfellowshipped way back in the Swinging Sixties I can't remember the reason for it I had a feeling it was for apostasy but it could have been as you say . I also heard later that he was back in the fold which surprised me at the time which makes me think he questioned the Org's doctrines.
I remember he was something of a charismatic speaker and gave good talks when I saw him in Lancashire UK. It was a shock at the time when I heard of his being made personna non gratis because I was young and gullible way back then but it eventually had a positive effect on me by making me start to realise that the Witness religion was just a cult and not as super duper as they like to make out.
I can picture him in my mind now he was a bit stocky and wore glasses in a suit and tie but they all had suits, I had a feeling he was from the Manchester area .
Ghosts from the past hey !