I am sure I read a trip report on here of at least one ex-LGW with the NNCW fitted?
Also, the TVs depend on the engine config of the 777 - smaller TVs = GE engines, larger = RR (hence all 744s have the bigger screens as they're all RR-powered...although I believe there is/was talk of the smaller ones being gradually replaced on the GE-powered planes too). BahrainLad is the usual expert here, but both LGW and LHR have some 777s with small and big TVs as a result of this. My MCO trip in April had the bigger screens, my DFW in March didn't...so it's a bit hit and miss...
Phil