Every dealer, seller and user must maintain and keep, for a period of three years and six months, all records of motor vehicle fuel or use fuel used, sold and distributed within Portland by such dealer, seller or user, together with stock records, invoices, bills of lading and other pertinent papers as may be required by the Tax Administrator. In the event such records are not kept within the state of Oregon, the dealer, seller or user must reimburse the Tax Administrator for all travel, lodging, and related expenses incurred by the Tax Administrator in examining such records. The amount of such expenses will be assessed in addition to the tax imposed by Section 17.105.010.