Cheers, lads!
I'm afraid it was a fruitless night. Turns out LSH3 doesn't like spaces in the title. Steam names the final folder with 3 spaces.
Fixed that issue and even got steam to still launch the game despite editing the spaces out in the folder (Edit the appmanifest file did the trick).
LSH3 all installed, wide-screen GUI enabled. Launched the game and was giddy to see the new splash screen and menu proving the mod was working.
I then moved the screen to the big TV, plugged the speakers in, grabbed a beer and prepared to set up (hopefully) the new steam controller for it.
Relaunched the game, grabbed a crafty hen to drink, click the mission, it began loading, only to stall with the loading bar all red...for ages.... Eventually realised it had crashed, swore abit.
Tried again, same thing. So called it a night.
Any ideas?
Specs:
I7 4790k
AMD Fury
16gb ddr3
Samsung evo SSD
Creative titanium PCIe