(1) No person shall erect or maintain any sign unless he has obtained a permit from the Department of Licenses and Inspections.

(2) No permit to erect or maintain any sign shall be granted unless such sign and the person seeking to erect or maintain it:

(a) complies with the requirements of this Section and the regulations issued under it;

(b) complies with all applicable provisions of Chapters 14-100 to 14-1800;

(c) complies with all applicable regulations of the Fairmount Park Commission.

(3) Subject to the provisions of §§ 14-1902(2) and 14-1903(1) and (2) a permit shall be granted for the continued maintenance of any sign lawfully in existence on March 28, 1946, without compliance being required with any of the other provisions of this Chapter.[477]

(4) Any sign lawfully in existence on March 28, 1946, shall not be repaired altered, or moved in any substantial manner unless it be made to comply with all requirements of this chapter and of regulations issued under it.[478]