The seller's own words, from the listing. Not checked by Sprinkle.
1939 Porterfield CP50 - Rare, Historically Significant Classic Seitz Aviation is proud to present an exceptionally rare 1939 Porterfield CP50, believed to be the only known flying example in the United States and one of only four known to exist worldwide. This Porterfield has a remarkable history spanning more than 85 years. The aircraft last flew in 1948, when it was flown to Yakima and its engine was removed for overhaul. While the engine was being repaired, a windstorm overturned the aircraft