Notwithstanding any other provisions of this article, any city located entirely within the boundary of any county proposing to consolidate with such county, and which becomes a tier-city shall have, mutatis mutandis, all the powers, duties and responsibilities of a town together with such additional powers as may be granted it by law, general or special. The appropriate provisions of the charter for such city may be made a part of the consolidation agreement and in that event shall become the charter of such tier-city, subject to the subsequent approval of the General Assembly. Such tier-city established pursuant to this section shall continue to exercise such powers and elect such officers as the tier-city charter may authorize and such other powers as tier-cities or towns exercise under general law. Except for those powers reserved to the tier-city in the consolidation agreement, the consolidated county shall exercise such powers in the tier-city as are exercised by counties in towns. Tier-cities shall receive from the Commonwealth financial assistance in the same manner and to the same extent as is provided towns. A tier-city may transfer all or part of the revenues it receives, the services it performs, its facilities, or other assets to the county by agreement of the governing bodies. The governing bodies may provide by agreement for the assumption of all or part of the tier-city’s debt by the consolidated county. The tier-city boundaries within the county may be established initially as agreed to and provided for in the consolidation agreement.