Rear brake line help

Zero chance you should re-use that TUBE. And you should take a very jaundiced look at the rest of the tubing, as well. I recently replace all the brake tubing in my 04 GMC which otherwise is very low rust. The tubing was a mess. I would guess that GM's recent choice of non-protection for the tubing was a factor. Worst looking tubing of any vehicle I've ever owned

The stores have various lengths, which are softer and easy to bend. You can also buy bulk tube various places, likely not locally