Many thanks to aidan (awegasm)... It was the grommet and aidan managed to get it off with brute force pushing the socket down over the rubber anyway to screw the half in spark plug back out.
Well done Aidan. nice work, and fixed what was initially thought to be a much larger issue (striped threads)
Great result! Much better than originally anticipated, lesson learnt, don't use cheap & nasty sockets in future.
Fixed! If you have a problem brute force can not solve that just means you are not using enough force.