Before I break something: any tips on body to rear axle brake line connector removal?

Thanks to all for the tips, guys!

There is a clip that secures hose to body tab.

Yup! There is a clip there somewhere. But it shouldn’t keep you from breaking the threads loose, it will hold the line to the tab though.

I think heat is probably you’re best option. Sometimes there’s just no way to save the car side line though. That metal brake line is 46 years old and is just plain steel. It may be rust damaged and pretty thin itself.

Ok...So I hope that two days of soaking in the penetrating oil will make that clip easier to see.
I'll hit it with the little torch (with the fire extinguisher near by) and give it a shot. I've got a pack of birthday candles on hand too. :D

Brian, you're right about the line. It could be toast. It really looks ok otherwise but I have a roll of brake line, bender, flaring tool and fittings all ready to go if necessary. I'm keeping my fingers crossed that it doesn't come to that!

I am grateful to Ma Mopar for using quality hardware though... Despite this stuck fitting, all of the lines and hardware on this car have held up astonishingly well, especially for a car that lived outside for much of its life.