(b) Except as in this article provided, no corporation organized or doing business under this article shall engage in the business of selling certificates or participations in obligations secured by mortgages.
(c) Except as provided in this article or in article sixty-five of this chapter, no person, firm, association or corporation shall, in this state, engage, or make any public proposal to engage, in the business of guaranteeing mortgages of real or personal property, or of selling any guaranteed mortgage or interest therein.
(d) Notwithstanding any other provisions of this article, no person, firm, association or corporation organized or qualified under this article shall in this state hereafter engage, or make any public proposal to engage, in the business of selling any mortgage, certificate of participation or interest in any mortgage or mortgages, or certificate secured by the deposit of any cash, mortgage or mortgages or other securities, coupled with any agreement to repurchase.