MR. WILSON IS HALF AS OLD AS HIS COUNTRY as he celebrates his Centennial the same year he celebrates his country's Bicentennial. Here he is wear ing his Uncle Sam hat as he holds congratulatory letters he received on his 100th birthday from President Gerald Ford and Governor Dolph Briscoe - Ad miring his huge red, white and blue cake decorated with U.S. flags is his great-grandson (grandson of Ruel Wilson.)