Repair Of Damaged Building. When a building, the use of which does not conform to the provisions of these regulations, is damaged by fire, explosion, act of God or the public enemy to the extent of more than seventy-five percent (75%) of its assessed value, it shall not be restored except in conformity with the district regulations of the district in which the building is situated. When a building, the use of which does not conform to the provisions of these regulations, is damaged by fire, explosion, act of God or the public enemy to the extent of less than seventy-five percent (75%) of its assessed value, it may be restored if the Board of Adjustment finds some compelling necessity requiring the continuance of the non-conforming use and the primary purpose of continuing the non-conforming use is not to continue a monopoly.