Section 16. If all of the persons appointed executors or administrators with the will annexed are the same persons as the temporary executors or temporary administrators with the will annexed, they may account for their administration as temporary executors or temporary administrators with the will annexed in their accounts as executors or administrators with the will annexed, and in such case no new inventory need be filed by such executors or administrators with the will annexed. A temporary executor or temporary administrator with the will annexed who is discharged or not appointed executor or administrator with the will annexed shall within thirty days after his discharge or the cessation of his powers render upon oath a true account of his administration including an inventory of all the deceased’s real and personal property which shall have come to his possession or knowledge unless he has previously returned his inventory.