In addition to the new cables, I would put new brake pads(shoes, blocks, whatever you call them). Your's are likely all dried out and hard from age. The old Scott/Mathauser salmon colored pads work wonderfully, but are not made anymore and hard to find. They come up on ebay from time to time. Koolstop also makes some good pads that should be available at your local bike shop. Be sure to clean the braking surface on the rims also. Any grease, oil, wax or other gunk will adversely effect your braking.