I've just come across this thread so sorry it's 12years late.
!. I was told that Chuck Pinkerton was George Pinkerton the speedway rider and later Squadrant- leader in the RAF during the second world war. He raced stockcars at Stepps Stadium not far from his rhubarb fields at Hogganfield Loch.
2. John Murphy also known as Spud Murphy rode speedway at Glasgow White city and also in Ireland at Shelbourne Park. He did not make the main team, but rode in second half events.