Upon such effective date of the merger of the Village of St. Johnsbury and the Town of St. Johnsbury the selectmen shall continue in office for the remainder of their respective terms and the other officers of the Town of St. Johnsbury shall continue in office until the first Tuesday in March next following, and their successors shall have been elected or appointed; and the ordinances of the Village of St. Johnsbury then in force shall remain of full force and effect, following the effective date of this act for a period of one year only, so far as such ordinances shall continue to be applicable and appropriate, except as repealed, amended, altered, or modified by the selectmen of the Town of St. Johnsbury, and as respects only that part of the Town of St. Johnsbury comprised within the limits of the Village of St. Johnsbury, as defined by No. 179 of the Acts of 1927.