The limitations on a local authority’s statutory power to dispose of houses acquired or appropriated for the purposes of Part V of the M1Housing Act 1957 shall not be taken to have prevented a local authority, at any time before 8th August 1980 (when the power of disposal conferred by section 91 of the Housing Act 1980 came into force), from granting to the tenant of a house an optionl to purchase the freehold of, or any other interest in, the house.