JF - Interesting experiences and the Holyhead connection rings bells. A Hastings en-route from Colombo to Changi was navigated by a Master Nav J M****. Near to the mid-point he called for a 90deg turn and followed it with a return to track some minutes later. On arrival at Changi, the crew checked with the RCC and discovered that there had been an opposite direction Hastings which had lost an engine and drifted down to the eastbound level. No tracking in those days so no hard evidence but ...
I was replaced as Sycamore winchman/winch Op in Aden by this same M Nav and knew him quite well, especially his ability to hypnotise people - me included!!.
Later still, the Holyhead connection, or, more particularly, Valley, when he and I were on the S&R flight at the same time for a while. During a Mess chat he mentioned that he was a member of a local white witch coven and offered me an introduction. Thank you but no thank you and off to Thorney not long after. Even after all these years (50) getting a 'handle' on these things is mentally niggling.