Exception.

  99.  Notwithstanding sections 96 and 97, a person is not guilty of an
offence under this Act by reason only that he transfers or delivers

  (a)  any restricted weapon to a person who carries on a business
  described in subparagraph 105(2)(b)(ii), or

  (b)  any firearm, other than a restricted weapon, to a person who
  carries on a business described in subsection 105(I) or subparagraph
  105(2)(b)(ii) for use in the course of that business.