Every producer shipping milk to a first purchaser outside of Iowa who is not by agreement with the commission collecting the tax imposed by this chapter , and every first purchaser within the state, and every producer distributing milk directly to the consumer, shall keep a complete and accurate record of all milk produced or purchased by the person during the period for which an excise tax levy is imposed under this chapter . The records shall be in the form and contain the information prescribed by the commission, shall be preserved by the person charged with their making for a period of two years, and shall be offered or submitted for inspection at any time upon written or oral request by the commission or its duly authorized agent or employee. [C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §179.6 ] 85 Acts, ch 126, §12 ; 86 Acts, ch 1238, §8