RCA CTC4B "Gainsborough" picked up in San Francisco

[miniman82]

Great picture, you can clearly see the portion that got zapped. What you're looking at here is the outer turns of the step up ring, which consists of very fine copper wire wrapped with a single layer of even smaller fibers. The burned portion has had its covering exposed, which is why it looks different from the adjacent turns. I would very carefully attempt to remove any remaining burned stuff with a microscope and dental tools, then apply melted wax with a small brush till they are again covered. You could then install it with the cage removed to see if it will work, then take it back out and finish building the tire back up. This is going to take time to get right, so take it one step at a time and don't rush. Those wires are close to the size of a human hair, doesn't take much to break them.