(1) A lease, or agreement for a lease or with respect to any letting, is not to be charged with any duty in respect of any penal rent, or increased rent in the nature of a penal rent, thereby reserved or agreed to be reserved or made payable, or by reason of being made in consideration of the surrender or abandonment of any existing lease or agreement of or relating to the same subject matter.
(2) A lease made for any consideration in respect whereof it is chargeable with ad valorem duty, and in further consideration either of a covenant by the lessee to make, or of his or her having previously made, any substantial improvement of or addition to the property demised to him or her, or of any covenant relating to the subject matter of the lease, is not to be charged with any duty in respect of such further consideration.
(3) An instrument whereby the rent reserved by any other instrument chargeable with duty and duly stamped as a lease is increased is not to be charged with duty otherwise than as a lease in consideration of the additional rent thereby made payable.