Dealers' and manufacturers' certificate of number, containing the word "manufacturer" or "dealer," as appropriate, may be used in connection with the operation of any motorboat in the possession of such dealer or manufacturer, when the boat is being used for demonstrative purposes. Application for a dealer's or manufacturer's certificate of number shall be made upon a form provided by the commissioner and shall contain such information as may be required by the commissioner. Upon receipt of the application and upon payment of a fee of $5 for the initial certificate of number, and $5 for each additional certificate of number, the commissioner shall issue to the applicant a manufacturer's or dealer's certificate of number which shall contain the word "manufacturer" or "dealer" in lieu of a description of the boat. The manufacturer or dealer may have the number awarded to him printed upon or attached to a removable sign or signs to be temporarily but firmly mounted upon or attached to the boat being demonstrated, so long as the display meets the requirements of the provisions of this article and regulations issued hereunder.