The article(s) in the Palm Beach Post on the Autorama have led me to some information about Bernard Thomas, who painted the America the Beautiful mural there.
As you know, the Autorama closed in October 1961. Someone bought the 153-foot mural to decorate a bar, but when they were unable to obtain a liquor license, the mural vanished. It was found in 1979 behind a real estate office in Boynton Beach, Florida. Gene Moore, the attorney who discovered it, contacted Bernard Thomas, then living in Boynton Beach, and asked him to restore it. Thomas restored it over the following six months. He and the Boynton Beach Rotary Club donated the mural to the Boynton Beach Womens Club, to be housed in their Addison Mizner-designed clubhouse.
Thomas, born in Sheridan, Wyoming in 1918, became a camouflage technician at the outbreak of WWII. Later he served in the US Army in Europe. At the recommendation of General George S. Patton, Thomas studied at the Ecole des Beaux Arts in Paris. Upon his return to the USA, he became known for his Western art and documentary murals. Thomas died in 1992.