(a) mobile home parks and single-family mobile home districts in existence on October 28, 1975, shall be permitted, provided the number of spaces shall not exceed those licensed or previously platted to such mobile home parks or districts on that date and provided further that such mobile home parks shall not exceed the limits of property also on that date under unity of title and shall be in accordance with state law.

(b) Removal and installation of a mobile home unit shall be done only after a permit is issued for this purpose by the building official.