(a) The invalidity of any portion of this Act shall in no way affect the validity of any other portion thereof which can be given effect without such invalid part.
     (b) Any election of an employer to be bound by the provisions of any Act that is repealed here, which election is existing at the time this Act becomes effective, is an election to be bound by the provisions of this Act to pay compensation for occupational diseases and for death resulting therefrom.
     (c) Any of the provisions of this Act that are the same as or substantially the same as any of the provisions of the Acts that are repealed herein shall be construed as a continuation of such prior provisions and not as a new enactment.
     (d) If in any other statute reference is made to any Act or section of any Act herein repealed, such reference shall be construed to refer to this Act or a substantially similar provision of this Act.