History PreservedBy Michael Smith, National Model Aviation Museum Director | michaels@modelaircraft.orgIN THE DECEMBER2023 issue of Model Aviation, my "History Preserved" article focused on a unique Control Line (CL) model that was built and flown by members of the Eugene Prop Spinners out of Eugene, Oregon. The Spirit of Exchange, sponsored by the Eugene Exchange Club, took off on September 1, 1957, flying nonstop for 64 hours and 33 minutes and ending its flight on September 3, 1957. Thirteen pilots exchanged the handles during the flight, covering an estimated 2,705 miles. The Spirit…