One of my instructors on the Dominie at 1 ANS, RAF Stradishall in 1968 was a Sgt navigator. His previous tour had been on Andovers. There was also a Master Navigator in Command Ops at HQSTC RAF High Wycombe in 1968.
I too flew with Taff Walker on the Wessex at Odiham, and he was a lovely bloke. The only problem was that he was really deaf; if you climbed into the LHS after he had vacated it, the intercom was so loud it blew your head off!