Notwithstanding the repeals of prior laws enumerated in section 30, chapter 157, Laws of 1973 1st ex. sess., actions for divorce which were properly and validly pending in the superior courts of this state as of the effective date of such repealer (July 15, 1973) shall be governed and may be pursued to conclusion under the provisions of law applicable thereto at the time of commencement of such action and all decrees and orders heretofore or hereafter in all other respects regularly entered in such proceedings are declared valid: PROVIDED, That upon proper cause being shown at any time before final decree, the court may convert such action to an action for dissolution of marriage as provided for in RCW 26.09.901.