Nothing in this Act shall be construed to diminish the independence of the Commission in making its determinations on claims in programs that it is authorized to administer pursuant to the powers and responsibilities conferred upon the Commission by the War Claims Act of 1948, as amended [50 U.S.C. 4101 et seq.], the International Claims Settlement Act of 1949, as amended [22 U.S.C. 1621 et seq.], and Reorganization Plan Numbered 1 of 1954. The decisions of the Commission with respect to claims shall be final and conclusive on all questions of law and fact, and shall not be subject to review by the Attorney General or any other official of the United States or by any court by mandamus or otherwise.