The provisions of this chapter shall not affect or operate to disqualify any investment which an insurer has made or which it is legally obligated to acquire prior to the effective date of this subchapter; provided, however, that an insurer at its option may transfer any previously made investment to the authority of the provisions of this chapter whereupon such investments shall be subject to and governed thereby. (Added 1967, No. 344 (Adj. Sess.), § 1 (ch. 1, subch. 5, art. 3, § 4).)