Carpets are a bastard to join, so I should have started at the back or at least practised on some scrap, but f*ck it, I just went ahead. On the plus side, it got better as I progressed and the last joints were pretty good. The first one was like a mad butcher had performed a C-section and sewed it up with baling twine.
Anyway, a quick trip up the loft, re-routed the antenna lead, bolted the TV to my cool-as-f*ck diy VESA bracket (fitted perfectly) and sat back to catch some tube (why tube? should be panel these days) The boob panel doesn't have the same ring to it.
I can report it works fecking well. I'll still have to cable up the other boxes and see about a proper screen (will pursue a Spandex/Lycra screen with foil behind) then fiddle with the projector projects.
Weird carpet, though - green in artificial light, blue in daylight.