If a safe-deposit box is made available by a lessor to one or more persons acting as fiduciaries, the lessor may, except as otherwise expressly provided in the lease or the writings pursuant to which such fiduciaries are acting, allow access thereto as follows:
(1) By any one or more of the persons acting as personal representatives.
(2) By any one or more of the persons otherwise acting as fiduciaries if authorized in writing, which writing is signed by all other persons so acting.
(3) By any agent authorized in writing, which writing is signed by all persons acting as fiduciaries.