Upon payment to the City Treasurer of the aforesaid tax, and upon exhibit of the City Treasurer's receipt therefor, it shall be the duty of the Tax Enforcement Administrator to issue to each licensee a certificate of license, signed by such Administrator, which must be displayed by the licensee in his or her place of business. Every certificate of license issued hereunder shall be numbered consecutively and shall show the name, place of residence, number of vehicles covered and the period for which the license is issued. The Tax Enforcement Administrator shall also issue to each licensee, in addition to said certificate of license, metal plates in duplicate, bearing the license number, year and descriptive term "coal dealer" or "oil dealer," and such metal plates shall be attached securely, one to each side of any and all vehicles used by the licensee to deliver such solid fuel or liquid fuel to an ultimate consumer within the City and shall be at all times prominently displayed thereon.