Section 43. Whenever a final decree in equity shall be made by the supreme judicial, superior, probate or land court directing that a deed, conveyance or release of any real estate or interest therein shall be made, and the party directed to make such deed, conveyance or release does not duly execute it within the time specified in the decree, the decree itself shall operate to vest title to the real estate or interest in the party entitled thereto by the decree as fully and completely as if such deed, conveyance or release had duly been executed by the party directed to make it.