(A) Non conforming signs, other than temporary or portable signs, lawfully in existence at the time of the adoption of this subchapter may be continued provided a required permit is obtained.
(B) No non-conforming sign may be enlarged or altered in any way which would increase its non-conformity.
(C) Should any non-conforming sign be damaged by any means to an extent of more than 50% of its replacement cost at the time of damage, it shall not be reconstructed except in conformity with the provisions of this subchapter.