Any type of housing including one, two and three family dwellings may be constructed under this section notwithstanding the provision that each project shall conform as nearly as possible to the existing published requirements of the federal government for low-rent or other housing projects. In offering for sale residences constructed under this section, preference to potential buyers shall be given whenever reasonably possible as follows: (1) veteran tenants of such residences; (2) all other World War II veterans, as defined in section seven of chapter four; (3) surviving spouses and parents of said veterans of World War II; (4) all other United States war veterans; (5) all other resident citizens of the city or town in which said residences are located; (6) all other citizens of the commonwealth; (7) an urban redevelopment corporation; and (8) all others. The provisions of this paragraph shall not apply to projects completed after July first, nineteen hundred and sixty-six.