Three souvenir postal covers individually signed in fountain pen or ballpoint by Richard E. Byrd (signed “R. E. Byrd” and postmarked March 6, 1931), Vilhjalmur Stefansson (postmarked November 13, 1937), and Hubert Wilkins (postmarked September 3, 1957, and carried on his flight over the North and South poles, with Wilkins adding the date of each flight). Light creasing, uniform toning and soiling, and show-through from envelope glue residue on Wilkins’ envelope, otherwise fine condition. RRAuction COA.