When a portion only of the gas or electric plant of any corporation would, under § 7-224, be included in a purchase by any municipality, such municipality shall, at the election of the owner or owners of such plant, similarly purchase all of such plant, instead of only the portion thereof employed as aforesaid in such business, for the benefit of consumers in such municipality. If such municipality believes the election of the owner of such plant last above provided for to be unreasonable, such municipality may, within thirty days after such election has been communicated to it, petition the superior court for the judicial district in which such municipality is located, for relief, and said court may, upon due hearing, if it finds such election unreasonable, modify such election and make such orders in the premises, including orders relative to the amount of property to be purchased, as it deems reasonable, and such municipality shall comply with such orders before establishing its plant for electric or gas lighting under the provisions of this chapter. Such municipality, upon such a purchase hereunder of the whole of any such existing plant, may thereafter continue to employ such remaining portion thereof, then used for the benefit of consumers, without such municipality, for its former uses and purposes, under the same powers, rights and liabilities with respect thereto as its previous owner enjoyed and was subject to.