Any company heretofore making deposits and registering policies pursuant to the act mentioned in section 246 shall keep and maintain such deposit with the Director in securities which are authorized for investment by life insurance companies under this Code. Certificates of purchase acquired by any company through foreclosure proceedings instituted by it upon mortgages in which its funds have been lawfully invested, and duly recorded conveyances of unencumbered improved real estate lawfully acquired by any company, accompanied by satisfactory evidence of ownership thereof shall likewise be eligible for deposit. The Director shall hold the title to such real estate so conveyed to him in trust until other satisfactory securities in lieu thereof have been deposited with him whereupon he shall reconvey the same to such company. The Director may cause such real estate to be valued and the company shall pay the reasonable expenses incurred in such valuation.