(a) Road districts shall be permitted to use funds that are on hand to pay valid outstanding debts of the district existing at the date of the passage of this subchapter.(b) Any part or portion of the three (3) mill county road tax by authority of law vested in or given to any particularly designated rural road improvement district shall be vested in the county in which the tax originates. It shall constitute a part of the public county road funds of that county. In special road improvement districts in counties to which funds have been advanced for use in completing any unfinished road, the improvement of which is authorized by the law creating the district, the board of commissioners of any such improvement district or any receiver in charge thereof is authorized and directed to repay the sums of money so advanced to any person advancing that amount out of any fund on hand which is not necessary for the payment of bonds of the district maturing prior to January 1, 1927, and accrued interest thereon.Acts 1927, No. 112, § 11; A.S.A. 1947, § 76-1212.