Lawrence T.Johnston of Worthington R.D.2;died Tuesday;Feb.1;1983;at 5:30 a.m.at his home.  He was 68.  Mr.Johnston was born July 11;1914;in Belle Vernon;a son of the late John Fullerton and Laura Kerns Johnston. A member of the Christian Church of Belle Vernon;he had lived in Worthington for the past three years.  Mr.Johnston was a former resident of the Dunlevy and Charleroi area;where he had lived for many years.  He was a retired truck driver for Corning Glass Works;Charleroi.  Survivors include his widow;Ruth Hatton Johnston;four daughters;Mrs.Robert (Carol) Grafton of Worthington R.D.2;Mrs.Jay (Norma) Finn of Aurora;Colo.;Mrs.Janet Smith at home and Mrs.Jerry (Linda) Hommey of Monongahela;one brother;Andrew Johnston of Belle Vernon and ten grandchildren.  Friends will be received in the Shelby D.Ferguson Funeral Home;700 Broad Ave.;Belle Vernon;on Wednesday from 7 to 9 p.m.and Thursday from 2 to 4 and 7 to 9 p.m.;where services will be held on Friday;Feb.4;at 1 p.m.with the Rev.Robert F.Bender;pastor of the Norwin Christian Church;officiating.  Burial will be in Belle Vernon Cemetery.  Shelby D.Ferguson;funeral director;is in charge of arrangements.