Sorry to sound like I am making a cheap point here Flower but
The men and woman who provide FIS on London Info are not ATCOs but FISOs hence why they cannot use a radar screen
is just like saying that my grandfather was a coalminer, my father was a coalminer, I am a coalminer and YOU MY SON are jolly damn well going down that mine too. My family's HONOUR depends on this tradition.
I bet you that every FISO would give an arm and a leg for a screen. As would most airfield "radio operators". The data is all digital so the cost of yet another feed is not a lot more than a 100 quid LCD screen. The data could be fed all over the place over the internet; HTTPS, (with GPRS/3G fallback).