Start at the frame, not the panel. On a house from the 1959 median build era, look for daylight gaps around the door edges - if you can see light or feel a draft standing inside the closed garage, the frame was likely never fitted with weatherstrip channels in the first place, not just worn ones. Check whether the track is original; older single-car tracks in this area often used lighter gauge steel that wasn't rated for the added weight of a modern insulated panel, which matters if you're planning a partial upgrade rather than a full replacement.
Also check the springs against the door's actual weight, not its listed weight when new. Wood doors especially gain weight over decades as they absorb moisture, even in a mild climate like this one, and a spring sized for the original 1960s door may be undersized now. One honest limitation: we can't tell you whether your specific door needs a panel swap or a full replacement without seeing the frame and hardware in person - photos help, but springs and track wear don't always show up in a picture.