No longer interested, as Warped Factor's post has pointed out that Luton Approach are not there, which would be why I was interested.
For anyone that likes this sort of thing, I can report that a visit to Farnborough Radar is well worthwhile... arranged through PPRUNE, together with 1013.25 about a year ago... very interesting, and provides wonderful insight and appreciation of what goes on on the other side of the mic!