Mich. Comp. Laws § 445.406

Sec. 6. If the purchaser or receiver, by exchange or otherwise, as described in section 3, is a peddler or goes about with a wagon to purchase or obtain by exchange or otherwise, any of such articles, and does not have a place of business in a building, he need not retain such articles for 15 days before selling them, provided on Monday of each week he files with the chief of police or chief police officer of the city or village in which he is located a report showing the place of business of the person to whom such sale was made; a copy of the record required by such section to be kept in a separate book of the articles purchased or received during the preceding week, including a description of such articles sold, to whom sold and his place of business.