Northolt Cessna

have a look at the excellent Northolt website http://www.northolt.biz/
If you look under residents and civil/other it reveals G-ATFY Cessna 172 was based in the 70’s.

G-ATFY is still around (last re-registered to its current owners on 14/12/2006):

G-ATFY Knott End – Beach Airfield 11-06-2011 – as found on flicker

The relevant part of G-INFO (the CAA database) for the 1970s is to be found here: http://www.caa.co.uk/docs/HistoricalMaterial/G-ATFY-1.pdf (owner based in Ealing London W5 from 4/11/1974 to 31/1/1977) and here http://www.caa.co.uk/docs/HistoricalMaterial/G-ATFY-2.pdf (owner based in Chiswick London W4 from 7/2/1977 to 8/8/1977)

G-ATFY is now apparently based in Essex and with its 12th owner from new (first registered – presumably new – on 8/7/1965)