On and after October 12, 1984, such appropriations [appropriations for the Bureau of Indian Affairs (except the revolving fund for loans and the Indian loan guarantee and insurance fund)] under this or any other act shall be available for: the expenses of exhibits; advance payments for services (including services which may extend beyond the current fiscal year) under contracts executed pursuant to the Act of June 4, 1936 (48 Stat. 596), as amended (25 U.S.C. 452 et seq.), the Act of August 3, 1956 (70 Stat. 896), as amended (25 U.S.C. 309 et seq.), and legislation terminating Federal supervision over certain tribes; and expenses required by continuing or permanent treaty provision.