For the purposes of this Part section 142 shall apply as if the following subsection were substituted for subsection (1):
"(1) A person shall not, at a particular time, be a director of more than -
(a) 25 unlimited companies (of whatever type), or
(b) 25 companies, one, or more than one, of which is an unlimited company (of whatever type) and one, or more than one, of which is any other type of company capable of being wound up under this Act.".