Wookey,
It seems most of the Trident crowd has congregated here, so why not stay here?
"....a moving map display which seemed to consist of a paper (?) scroll and a moving pen?"
Ah, you're opening a new can of worms as well!
No, the scroll was some type of Mylar, and the moving pen was a moving marker.
But I'm as curious as you to hear a bit more about its workings!
By the time Concorde came around, they'd progressed to a projected moving map display, using projected maps stored on film.
And in the case of Concorde it was thrown out almost as soon as it arrived... a bit useless over water, and replaced by the INS.
Only the prototypes had it, and even then only in the earlier days.
CJ