1123.03 SUBSTITUTION.
   The Planning and Zoning Board may allow the nonconforming use of a building or structure to be changed to another nonconforming use of the same or of a more restricted classification, provided no structural alterations except those required by law or ordinance are made. However, in an "R" District, no change shall be authorized by the Planning and Zoning Board to any use which is not a permitted or conditional use in any "R" District.