If the cable has the fixed soldered tips on both lever and caliper ends, you could just buy new whole cable assemblies or even have them made. I wouldn't want to risk my safety just because of the look of a 70+ year old cable. Going back to the original question, of the cable needs lube, that means somewhere in that housing it is almost certainly worn, maybe not enough to fray, but is that worth it? Compound that probably worn cable with the extra force you are going to need to use because the pads are also 70 years old, and you may just miss that stop sign or stoplight, at the wrong moment. Maybe this is just a display bike? Just my $.02.
Phil