§ 4. Exemption from certain excise and sales taxes granted to the United Nations. Excise and sales taxes imposed by the state upon the sale of tangible personal property shall not be exacted or required to be paid by the United Nations upon and with respect to any sale of tangible personal property hereafter made, provided the property is acquired for the official use of the United Nations; and the provisions of any law now in force or hereafter enacted imposing any such tax shall not apply to sales of tangible personal property to the United Nations. The state tax commission shall make such reasonable rules and regulations as may be necessary to give full force and effect to the provisions of this section.