The movie starts in the Kremlin in 1953, where Joseph Stalin (played by Maurice Manson) indulges in his fetish by watching a woman having her head shaved. He then undergoes plastic surgery, watches the people gathering to mourning his death, has the doctor who performed the surgery shot, and then vanishes from the story. For a while, anyway.
In Berlin, former OSS agent and PI Lex Barker tries to gives Zsa Zsa Gabor her money back. She hired him to track down her sister, but never mentioned that she was working in the Kremlin. After she offers him more money, he goes back to work, and decides that Stalin is still alive. But where? There's spy stuff.
I strongly suspect this is an updating of an unproduced script for just after the War, in which Hitler has been replaced by Stalin. It's strictly cheap fare from producer Albert Zugsmith, and the only names I recognize are William Schallert as Stalin's son, and DP Carl Guthrie.