In the winding up of a corporation, any director, whether past or present, whose liability is under the provisions of this Act, unlimited, shall, in addition to his liability, if any, to contribute as an ordinary member, be liable to make a further contribution as if he were, at the commencement of the winding up, a member of an unlimited corporation :
Provided that—
(a) a past director shall not be liable to make such further contribution, if he has ceased to hold office for a year or upwards before the commencement of the winding up;
(b) a past director shall not be liable to make such further contribution in respect of any debts or liability of the corporation contracted after he ceased to hold office;
(c) subject to the articles of the corporation, a director shall not be liable to make such further contribution, unless the liquidator deems it necessary to require the contribution in order to satisfy the debts and liabilities of the corporation and the costs, charges and expenses of the winding up.