As a child in the 1950's I remember hearing the approaching "Tok Tok Tok" of helicopter rotors and rushing outside in excitement. Back then, helicopters were not common, and the rare birds we saw were the Military H-34.
The Sikorsky H-34 "Choctaw" was a piston driven aircraft designed for service in the United States Navy for anti-submarine warfare. It's tremendous lift capacity was soon put to use transporting troops and cargo. It served in Viet Nam in the 1960's and 70's and worked as a rescue vehicle over water and rugged terrain. It retrieved astronauts for NASA's Mercury space program and transported United States Presidents. Though a few of the turbo powered birds are still in civilian use, it is rarely seen outside of an air museum today. The largest single remaining group of these retired aircraft was shredded and sold to Vietnamese scrappers in 2011. This one survived.
Piece by piece, the few remaining parts are being located and renewed. You can read about it and see it's progress in the Mantiques blog.