Should any section or provision of this chapter or the application of any provision to particular circumstances be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any part thereof other than the part so declared to be unconstitutional or invalid. In such case, should any section or provision be declared invalid or void, and the effect would be that there be no zoning, regulations or standards in effect which would be applicable to the particular lot or situation, then the zoning, regulations and standards which were in effect and adopted pursuant to Ordinance No. 493, enacted August 10, 1965, shall apply.