[C320-list] Mainsail furling screw update

[Fishbust]

An update to last weeks dilemna...

Furling mainsail control line needs replacement. SS Retaining screw into aluminum, saltwater boat 18 years old threads galled won’t come out....

Today tried heat, tried kroil, tried impact driver, it won’t budge. I am beat up. New plan is to uncouple furling screw and pull the whole assembly out and put it in a vice and either get it out with a pipe wrench or snap it off and start drilling. 

Any other ideas or a diagram what is holding the furling screw in would be appreciated. No manufacturers name on mast. 2002 C320, hull number 902. 

Thanks all.    Joe.