Oh god! That means I shall start all over again... End of the world for me as I've spent around 8 hours on it.
I was kind of going through the same route as you've explained -ish eventually but clearly detonated the whole thing by extracting the faces in the first place. Now I realise once the pieces are cut off in the perspective one cannot sew them back on in the uv editor.
Is 'Mastering UV Layout' the tute you're referring? I might as well learn it proper from a Jedi like yourself.
Great work on the Ender's game, by the way.

Many thanks for your time and wisdom.