[Hugh R]

Threads look kind of chewed up. I'd consider a thread chasing tool. Very dangerous if you don't know what you're doing. I cross threaded a plug once and ended up pulling the motor to get a straight shot at it. My brother, a Jet Propulsion Laboratory machinist said "Do you want to eff it up or do you want me to fix it". Wise words, he retapped it and it was magic what he was doing in terms of gauging the hole and getting back the threads.

Don't just try and run another spark plug into it, you may well make it worse.