There is established as of June 30, 1956, a Community Disposal Operations Fund, and the Commission (or the head of such agency as may be carrying out the sales and financing functions of the Commission pursuant to a delegation by the President under section 2313 of this title) is authorized to credit said fund with all moneys hereafter obtained or now held by it and to account under said fund for all assets and liabilities held or acquired by it in connection with its sales and financing functions under this chapter, and to make temporary advances to such fund, from any other funds available for expenses of operations of such Commission or agency, as may be required to carry out such functions pending the realization of sufficient proceeds under the provisions of this chapter: Provided, That any such advances shall be repaid to the source appropriation or fund, to the extent of any unobligated balances available in the Community Disposal Operations Fund, prior to the close of the fiscal year during which such advances are made.