Any nonconforming sign as defined in Section 40-6-5 that does not pose an imminent peril to life or property may lawfully remain subject to all the restrictions on the enlargement, alteration, or relocation, or reconstruction of nonconforming structures set forth in Article VIII of this Code; provided as follows:
(A) Merely changing the message displayed on a nonconforming sign shall not be construed as a prohibited alteration;
(B) Whenever any sign is nonconforming solely because it is appurtenant to a nonconforming commercial/industrial use located in the Agricultural District or in any residential district, said sign shall be treated in the same manner as it would be if it were appurtenant to a commercial/industrial use located in any Business District or in the Industrial District.