Rethreading spot welder tongs?

I have an old Dayton 2Z543 hand held 115V spot welder. The tips screw into the tongs, but the threads are stripped. Been using it that way for a decade, but it's got to the point that I'm burning holes when the tips tilt and the contact area is small.

Any options to repair this without spending $91 on new tongs?

The copper is rather soft, so if I could just compress the end a little and re-thread the tongs and replace the tips, I'd be good to go.

If I squeeze it in a vise, I'll just make the hole oblong. I have a substantial V-block and a press, maybe three sides will be enough??? I don't know much about the dynamics of metal forming. Would pounding on it with a hammer in the V-block work better than trying to squeeze it?

Anybody got a trick for getting compressive force on multiple sides to shrink it.

Or maybe a highly conductive heli-coil?

Thought I'd get some advice before I made a mess of it.

I rarely use it, so the "fix" doesn't have to be production quality.

Ideas?

Thanks, mike