Ditto the advice to adjust the brakes before replacing anything. Those pads look fine. Heck, the whole bike appears to be in excellent condition, with plenty of attention to detail, from the cable housings on up. The pads don't look old enough to be a problem. Maybe scuff 'em up with sandpaper or a file, but first go through the steps to adjust the brakes.
Most can't-deliver brakes are a PITA to set up. Check several tutorials and videos. It'll take a few tries to get 'em right, but worth the effort so you'll better understand how they work.
The main adjustments are in the cables. Helps to have a third-hand tool, but I'm too cheap. I use velcro straps, small bungee cords, paracord or even shoelaces to hold the cantilever arms and brake levers in the desired position. Non-elastic paracord or shoelaces can be easier to use for some adjustments, with a mariner's hitch to hold position temporarily, untie and retie quickly. Ordinary knots can make it more difficult. Check online for diagrams of sailor's hitches and fisherman's knots. Saves a few bucks over buying a third hand tool that we'll rarely need at home.
Watch out for brake shoes rubbing the tires. That's one of the main hassles setting up can'tdeliver brakes. With the brakes open it'll look like there's plenty of clearance. But when the brakes are closed, darned if the shoes don't develop a mind of their own and try to rub the tire sidewalls.
While you're at it, check the spring tension position of the brake arms at the frame. There are usually three positions. Most manufacturers assemble them with the stiffest position and most spring tension. Usually unnecessary.
For a couple of years I just tweaked my '92 Univega's canti brakes in bits and pieces. Finally a few months ago while recuperating from surgery, I redid the entire canti brake setup on my Univega, from cables and housings to pads, etc., including setting the spring tension to the middle position. Improved the brakes from can't-deliver to cantilever. Better feel, better braking power with better modulation.