You mean an M65 like this one?
Developed by Picatinny Arsenal. Manufactured in Watervliet, NY. Photo taken at the Virginia War Museum.
Of the twenty examples of the M65 produced, at least eight survive on display.
United States Army Ordnance Museum, Aberdeen, Maryland (still has the two large "prime movers" attached)
National Museum of Nuclear Science & History, Albuquerque, New Mexico
Fort Sill Museum, Oklahoma
Freedom Park, Junction City, Kansas, overlooking Fort Riley
Rock Island Arsenal, Memorial Field, Rock Island, Illinois
Virginia War Museum, Newport News, Virginia
Watervliet Arsenal Museum, Watervliet Arsenal, Watervliet, New York, where they were all manufactured.
Yuma Proving Ground, Yuma, Arizona