It's a funny movie. Clint Eastwood, Telly Sevalas, lots of the stars from my era. (and Donald Sutherland, Keefer's father, is a "Hippy" type 20 years before there was anything called a hippie.)
It's a gold heist in the middle of WWII. Not historically accurate. But fun to watch the "wheeling and dealing" that goes on.
Don't take my word for it, Do your own research! Then you will know it's true!