Uses and structures formerly situated in the Business District under the Zoning Ordinance of 1921, now in the Residence District, may alter their uses to a use permitted under § 164-32 with the approval of the Board of Trustees after a public hearing and may, with the approval of the Board of Trustees after a public hearing, upgrade their structure for safety, fire protection, improvement of energy performance of the structure, and/or aesthetic purposes and/or to reasonably enable the new use permitted under § 164-32. Repairs to both structural and non-structural parts or incidental alterations may be made to and/or in a structure substantially utilized as a nonconforming use, and/or in connection with a permitted change or extension of a nonconforming use. A legal nonconforming use and/or structure, unless there has been an abandonment of the nonconforming use and/or nonconforming structure, shall not be deemed to have lost its legal nonconforming status. A legal nonconforming use and/or structure, even if changed to be a conforming use and/or structure, unless abandoned, may thereafter be changed or returned to any nonconforming status applicable to the site.