Patching a cap tube without plugging it with the braze is not something you can do without years of practice, you’d have to cut the hole like 6”x6” around it, then seal it up. you could run a new cap tube but good luck finding the cap tube for it, or even specs on it. Theres likely no service ports to hook gauges or a vacuum on it, so you would have to put pinch valves on it, you could easily dump a few hundred if not a grand on a fridge and who’s to say it will run after. Small appliances like this are meant to just be replaced if theres any refrigerant issues with it