Complex sentence: This Gull is currently the only air-worthy example of either the Gull 1 or Gull 3 left in Britain, the only other airworthy Gull 1 going to the United States in 2010.
Split into simpler sentences: This Gull is currently the only airworthy example of either the Gull 1 or Gull 3 left in Britain. The only other airworthy Gull 1 went to the United States in 2010.