Since we have not heard back from the OP if the problem has been fixed, the issue can be from a number of things as can be gathered from the responses. As the OP stated, Old Camera, dark fields leading into the Negatives. Both strong indications of light leaks. Other options: Bromide Drag from too little aggitation Sprocket Surge (surge lines) from over aggitation I have even seen similar issues from using a dirty reels with too much wash agent left on them, causing increased development around the sprocket holes. Film being too tightly wound in the camera can cause this.