All official zoning maps of the Borough of Newtown approved prior to the adoption of these Regulations shall remain on file in the Office of the Town Clerk, but shall be considered merged into the Zoning Map referred to in 3.02. Said maps shall have validity only to the extent that a court of competent jurisdiction finds them necessary to determine the location of a zoning boundary which it finds not determinable from the map referred to in 3.02 hereof.