[fred cook]

Once, long ago I was restoring an Alfa Romeo Gulia Spider with drum brakes, very unobtanium drum brakes! Each side had 3 aluminum shoes with rivited linings, 3 wheel cylinders and steel lined finned aluminum drums. The brake linings had been soaked very badly in oil and brake fluid and would have to be cleaned or replaced. This being in Georgia in the early 1970s, I did not know of a shop that I trusted to replace the linings without possibly damaging the shoes. So, I went thru a process of soaking the linings in gasoline and then burning it off. After each burning I would use a wire brush to scrub the surface of the brake lining. It took a dozen or more treatments to finally get the linings clean in appearance and to the touch. When reassembled, adjusted and bled, they worked quite well. So, I guess the question that you have to answer is, how much is your time worth, knowing that if your cleaning is not complete you will have to pull the engine again? If it was me, I would buy a new disc.