(2) If the Department of Revenue finds that a taxpayer designs quickly to depart from the state or to remove the property of the taxpayer therefrom, or to do any other act tending to prejudice or to render wholly or partially ineffectual proceedings to collect the tax for any past tax year or the tax year then current unless such proceedings be brought without delay, the department shall declare the current taxable period for such taxpayer immediately terminated and shall cause notice of such finding and declaration to be given the taxpayer. Simultaneously, the department, on the basis of the best information available to it, shall assess a tax for such terminated period and for the preceding tax year (if no return has been filed therefor, whether or not the time otherwise allowed by law for filing such return and paying the tax has expired), and shall assess additional tax for any years open to assessment under the provisions of the applicable law. The department shall give notice to the taxpayer of all taxes so assessed. Such taxes shall thereupon become immediately due and payable as soon as the notice and findings are issued to the taxpayer or mailed to the last-known address of the taxpayer. In any proceeding in court brought to enforce payment of taxes made due and payable by virtue of the provisions of this section the findings of the department, made as provided in this section, whether made after notice to the taxpayer or not, shall be for all purposes presumptive evidence of the taxpayer’s design and the certificate of the department of the mailing or issuing of the notice and findings specified in this section is presumptive evidence that the notice and findings were mailed or issued. [1957 c.632 §20 (enacted in lieu of 316.640, 317.440 and 317.445)]