Notwithstanding any other provision of existing law, the trust funds credited to the Shoshone Tribe and the Arapahoe Tribe, respectively, under the provisions of this subchapter shall be available for expenditure or for advance to the tribes for such purposes as may be requested by the business council of the tribe concerned and approved by the Secretary of the Interior, or such official as may be designated by him: Provided, That the Secretary of the Interior is directed to make available out of the trust funds of the Shoshone Tribe the sum of $7,500 for the purpose of making emergency and educational loans on the authority and responsibility of the Shoshone Tribe, through its business council, without liability to the United States and free from regulation or approval by the Secretary of the Interior: Provided further, That, commencing as soon after August 8, 1958 as the Secretary of the Interior determines may be practicable in order to change from the existing quarterly payment system, but not later than January 1, 1959, 85 per centum of said trust funds shall be paid per capita to the members of the respective tribes in equal monthly installments on the first day of each month, or as near thereto as practicable, or with the approval of the Secretary of the Interior, at such more frequent intervals as the tribes may request. The amount of the monthly payments during any one calendar year shall be determined by the Secretary of the Interior on the basis of estimated anticipated income for that calendar year: Provided further, That the Secretary may increase or decrease the amount of the monthly payments in the light of actual receipts during the calendar year, and in order to avoid the omission of a payment or a reduction in the amount that would cause unnecessary hardship the Secretary may permit the total monthly payments for a year to exceed 85 per centum of the actual receipts for that year and deduct the excess from the receipts of the following or succeeding years before determining the amount of the monthly payments for such succeeding years: Provided further, That said per capita payments shall not be subject to any lien or claim of any nature against any of the members of said tribes unless the business council of such member shall consent thereto in writing, except as to reimbursable Treasury loans made to individual members of either tribe which may be due to the United States, and except as to irrigation charges owed by individual Indians to the United States with respect to lands for which water is requested and received by said individual Indians, and with respect to lands that are determined by the Secretary of the Interior to be properly classified under existing law on the basis of the survey undertaken by the Secretary after the amendment of this section on July 25, 1956 (
70 Stat. 642): Provided further, That quarterly per capita payments under this subchapter shall continue without interruption until the monthly per capita payments are put into effect on or before January 1, 1959.