Brakes are gone!

If the lines are rusting through, I would get ready to replace the rubber hoses as well. Up here in salt country where brake lines and the rest of your vehicle rust away as you watch by the time the lines rust through all the flare nuts going into hoses and wheel cylinders are just little rusted round blobs of metal welded into the mating piece. Around here you start at a wheel cylinder and before you know it you are at the distribution block.

But, for sure get yourself a good tubing wrench so you don't round off the flare nuts on your new lines as you install them. Good luck on getting things a part and repaired. I'm sure you will carefully inspect all the lines on the car. So often, one bad line means there are others waiting to go next.