No I'm not the bloody stupid fooking thing. Went and bought a blow torch and everything!
It looks like that is the next option. Need to find a mig welder I suppose. :/ other 3 were absolutely fine. Did notice there was a bit of oxidation around the injector so maybe water has caused a problem leaking or running of the inside of the bonnet or something?
Oh well. Keep at it I suppose. At least it's still drivable
For now........ Got a clunk when I pull away and change gears coming from the rear part of the drive train. It's Christmas for parts!