The ends to the brake rod and to the backing plate should be the same. The rear brakes will be a little longer, due to the increased travel of the rear suspension. No difference right to left. You could use a rear on the front and just have a bigger "loop' in the flexible portion, but moving a front to back would not be enough for suspension travel. I'll bet new cables have been needed for years across several makes, but I'm not sure where you would go for getting them reproduced.
Does anyone know what happened to Reg Bent's part stash? He moved a while back and his collection was sold. He sold me the back brake assembly for my 614 about 20 years ago, but I seem to remember him saying that he had a couple of extras. Maybe an old lead, bit a lead none the less.
Where Are You From? Ottawa, Ontario, Canada
Do You own a car built by Durant? 1931 Duraant 614
I took a cable off my spare front axle and guess what? Same length and ends. Prolly a different mfr but sure looks like a fit. It is free, cable slides in the conduit. Only difference is it has a cloth protective cover. Frank is going to check his stash and I’ll keep my eyes and ears open. But I think I have a path to finish. I took a pic of them side by side but I’m not smart enough to upload it here. Got my spare parts from Frank Johnson years ago.