As far as I know, all LGW 777s have been fitted with NCW seats. There may be one still lurking about with old style seats (recently "nabbed" from LHR), but I'm pretty sure it's due to be fitted shortly. The aircraft in question is being used (as previously mentioned) on the MLE/SSH routes, so you should be in an all new and shiny cabin.
Please do get in touch via PM if you need more info about the cabin/facilities.
Gg