Any lawful use of property existing on the date of the adoption of this Ordinance which does not conform to the regulations prescribed herein shall be deemed a nonconforming use and may be continued subject to such regulations as to the maintenance of premises and conditions of operations as may, in the judgment of the Planning and Zoning Commission be reasonably required for the protection of adjacent property. A nonconforming use may be extended through an existing building provided no structural alterations, except those required by law or ordinance, shall be made therein, and if no structural alterations are made, a nonconforming use of a building may be changed to another nonconforming use of the same or a more restricted classification. A nonconforming use, if changed to a conforming use, may not thereafter be changed back to a nonconforming use. If a nonconforming use is discontinued for a period exceeding six (6) months, such nonconforming use shall be deemed to have been abandoned and any future use thereof shall conform to the terms of this Ordinance.