Just shooting from the hip, here, but Decca should release an all-analogue box set of Solti's Mahler. London SO versions of M1, M2, M9 and Chicago versions of M5, M6, M7, M8, and DLvdE. I have never heard his London SO M3, but have read that it is dreadful (IMO his digital Chicago one is dreadful). I don't believe that he has an analog M4. His digital Chicago one is passable, but nothing special.