This probate code shall take effect and be in force on and after January 1, 1964. The procedure herein prescribed shall govern all proceedings in probate brought after the effective date of this probate code. It shall also govern further procedure in proceedings in probate then pending, except to the extent that, in the opinion of the court, its application in particular proceedings or parts thereof would not be feasible or would work injustice, in which event the former procedure shall apply.

 No act done in any proceeding commenced before this probate code takes effect and no accrued or vested right shall be impaired by its provisions. When a right has been acquired, extinguished, or barred upon the expiration of a prescribed period of time governed by the provision of any statute in force before this probate code takes effect, such provision shall remain in force and be deemed a part of this probate code with respect to such right.