The inventories herein required shall show the name, description, serial number, purchase or construction date, and the cost or purchase price of each article or piece of property, and any further information which the state auditor may require. A number shall be securely attached to each piece of furniture, equipment, or other property designated by the auditor not having a serial number, and the number shall be used in inventories as a serial number. Estimates may be used for purchase prices and dates on items purchased prior to January, 1946, provided records of same are not available.