An existing legal non-conforming tavern or restaurant existing on December 1, 1975, or an existing tavern or restaurant which becomes non-conforming because of a subsequent change of zoning district classification, may be issued a liquor license in accord with the provisions of Chapter 801, SLCRO, 1974, as amended, and such issuance and sale of liquor thereunder shall not be deemed an enlargement, extension, or alteration of said use.