With everything finally off, and cleaned everything (carbon, oil, etc) up with Winn's Carb/Injection Cleaner and grease every orifice and moving part on the TB. The previous accident was replaced with the old base, and everything was assembled together with new bolts.
The gasket had also, er, 'perished'. To say the gasket would've been 'okay', would've been an insult to the entire heritage of engineering...
And here's what the official Mitsushitty Throttle Body Gasket looks like:
Previous to all this malarky, I was squirting Carb Cleaner into various pipes, and took a video of the the throttle during engine running and after it cuts out. I'm not sure if it should be doing this with the engine NOT running? The car cuts out at 00.50 and it starts dancing like a worm in traction at 00.56.
... not sure what to do now, other than wait for a new gasket and Coolant Temp Sensor. I've been told to flush the whole fuel system and put new filters in, which is a good idea.