Assets could range over $50 Billion if you count the DIA's collection, Belle Isle, and the water department. Looks like the real estate and the paintings should cover things.
Total debt is about 19 billion with the majority being the Pension Liabilities. Orr does not want to sell the "Assets" you mentioned to leave something for civic pride and some cornerstones to rebuild the city on.
Belle Isle will probably get some sort of a State deal being floated, with the H20 Dept going regional with new management already cleaning up that cesspool.
The DIA, that it up in the air, again Orr doesn't want the city pillaged like something out of warn torn Europe, I give him kudos for the Optomistic attitude.