Welding is probably not a viable, much less cost effective, answer. Because the brake bridge was brazed in the first place (1982 you say, right?) there is brass in the joint and would have to be completely cleaned out prior to a weld. You would have to have the joint re-brazed. Most likely the paint damage would indeed be isolated to the area around the brake bridge and could easily be covered up with a little spray. Have you looked around on fleabay or CL for another frame perhaps? You may be able to simply find a similar frame from the same period for the same or a little more than the repair would cost and you wouldn't have anything to worry about in the future.