No lawfully existing sign which fails to conform to the provisions of this Article 6 need be removed or altered to conform to said provisions prior to the end of its normal life as provided in Section 604 of this Code, except as specified in Sections 609.1 through 609.12. Where two or more amortization periods of differing duration apply to the same sign, the most restrictive of such amortization periods shall prevail unless this Code specifically provides otherwise. Where removal or alteration of a sign is required, such requirement shall apply to the sign faces, the sign structure, the supporting framework and all other parts of the sign.
(Amended by Ord. 64-77, App. 2/18/77)