Stan,
When the hinge pin is replaced, it would be replaced with a larger diameter one to take up the wear( or in the case of your barrels abuse). The fitting of the hook to the hinge pin would be done by "Spot" and "scrape". If the barrels are canted, it wouldn't hurt to check the lugs for fit in the receiver, they shouldn't be able to close canted. There is no doubt that you are better with a mill, than I (everybody is better); but if I tried to straighten this problem out with a mill, I would have it so screwed up, I couldn't sell it for scrap iron. With a scraper, you can take less and take it in a limited area, where the smoke or Prussian blue tells you to take it.
Mike