That is/was the Heathrow Approach radar video map depicting east/west parallels, 23/05 and Northolt 25/07 (which is offset). The 23/05 'parallels look like PPI 'shift' burns on the phosphor. (I think I have similar burns on my retinae....). The crosses are NDBs and the squares are the minor aerodromes. The kit is a couple of decades too late for 23L and 23R! I would put that tube at about '89 when the CTB ground floor approach room was opened. I seem to recall that they were replaced with flat Sony Eriksson displays which then became redundant in '93 when Heathrow approach moved to West Drayton. (A four-year life for a very expensive expensive approach control facility...!) On the other hand that tube might be from the Training section sim. Hazy memories now.
Any comment from 'Heathrow Director'?