Super-Rare Twin Mustang Takes To The Air After Ten Year Restoration Warbirds by Chris Clarke - 01/03/201908/27/20190 Of the five Twin Mustangs left in the world, two are on display in the National Museum of the United States Air Force in Dayton, Ohio. Another is a gate guard at Lackland AFB in Texas. One is currently undergoing restoration. And one—just one—is, at