As not much response to my suggestion that a new thread on AH&N might elicit more fascinating insight into this aircraft maybe a new technical question - Mods feel free to move/delete or suggest a completely new thread if you feel too much thread creep here!!
From my few visits to the 'Best Seats In The House' end of the Trident I recall that it apparently had a moving map display which seemed to consist of a paper (?) scroll and a moving pen? I cant imagine how this worked let alone how you guys used it on longer sectors.