The budget or the orders, motions, resolutions, or ordinances as may be required to authorize the expenditures proposed in the budget as finally approved; and any orders, motions, resolutions or ordinances to increase the total amount authorized for expenditure adopted shall remain on file for three years and shall be public records and open to inspection. To each copy so filed the budget officer shall attest to the fact that preparation and adoption procedures were conducted in the manner prescribed herein.