No provision of this article shall be construed to require the dissolution of any historic development commission or architectural review board created by an ordinance enacted pursuant to prior laws. Any historic development commission or architectural review board created by an ordinance existing pursuant to prior laws and existing at the time of the enactment of this article shall continue in existence and shall have all of the purposes, powers, and authority set out in the ordinances creating such commissions and boards. Any such commission or board shall also have the power set forth in this article, if so provided by ordinance enacted by the governing body creating the historic development commission or architectural review board.