Need Cylinder Advice A65

[Captalbertq]

Today I removed my spark plugs for cleaning and #1 bottom felt funny unscrewing as it has before and when reinstalling the plug, the Heli-coil peeled out of the cylinder. Obviously I'll have to remove and repair or replace. I reviewed my engine log and it was majored in 1980, 750 hrs since. It has three .15 over pistons but this cylinder was chromed to standard. I briefly looked at Millennium but see they are currently unavailable. Any guidance would be appreciated.

Thanks, Albert 😕

 

[JimC]

 

[Captalbertq]

 

[Renkou1]

 

[JimC]