73.—Where, immediately before the commencement of the Landlord and Tenant (Ground Rents) (No. 2) Act, 1978, a person was, as respects any land, a person to whom section 3 of the Act of 1967 applied or would have been such a person if he had served a notice under section 4 of that Act, he shall as from such commencement be a person to whom Part II of the Landlord and Tenant (Ground Rents) (No. 2) Act, 1978, applies.