Russruspy if I recall correctly the unit shown as Indicator BC 929 in ZH875's link resembles the unit fitted to the nav. trainers. Except I think our scales were 12, 60,120 n.m and there was a knob for selecting channels (6 may even 8 of them). The unit was mounted flush in the nav. panel and what you are describing as "a bit like a telescope poking out" is the anti glare shield. A tube fitted over the crt display with a shaped end to stick your forehead on with a cut out for one's nose. This end had some sorbo rubber on it. The thing looking like a megaphone with a rectangular open end.
Edited to add that on the NF(T) 10 Vampire this hood was normally detached from the unit for stowage. But I can't find a picture of this either.
Last edited by Pom Pax; 21st Jun 2010 at 18:55.